Agilent Technologies 34401A User Manual

Agilent 34401A  
6 ½ Digit Multimeter  
User’s Guide  
Agilent Technologies  
Safety Information  
General  
Safety Symbols  
WARNING  
Do not use this product in any manner not  
specified by the manufacturer. The protec-  
tive features of this product may be  
impaired if it is used in a manner not speci-  
fied in the operation instructions.  
Earth Ground  
Main Power and Test Input Dis-  
connect: Unplug instrument from  
wall outlet, remove power cord,  
and remove all probes from all  
terminals before servicing. Only  
qualified, service-trained person-  
nel should remove the cover from  
the instrument.  
Chassis Ground  
Do not install substitute parts or perform  
any unauthorized modification to the prod-  
uct. Return the product to an Agilent Tech-  
nologies Sales and Service Office for service  
and repair to ensure that safety features are  
maintained.  
Risk of electric shock  
Refer to manual for addi-  
tional safety information  
Ground the Instrument  
If your product is provided with a ground-  
ing-type power plug, the instrument chassis  
and cover must be connected to an electri-  
cal ground to minimize shock hazard. The  
ground pin must be firmly connected to an  
electrical ground (safety ground) terminal at  
the power outlet. Any interruption of the  
protective (grounding) conductor or discon-  
nection of the protective earth terminal will  
cause a potential shock hazard that could  
result in personal injury.  
WARNING  
Alternating Current  
Line and Current Protection  
Fuses: For continued protection  
against fire, replace the line fuse  
and the current-protection fuse  
only with fuses of the specified  
type and rating.  
On supply  
Off supply  
‘In’ position of bi-stable push  
switch  
Cleaning  
WARNING  
Clean the outside of the instrument with a  
soft, lint-free, slightly dampened cloth. Do  
not use detergent or chemical solvents.  
‘Out’ position of bi-stable  
push switch  
Front/Rear Switch: Do not  
change the position of the  
IEC Measurement Category II.  
CAT II (300V) Inputs may be connected to  
mains (up to 300 VAC) under  
Category II overvoltage condi-  
tions.  
Front/Rear switch on the front  
panel while signals are present on  
either the front or rear set of ter-  
minals. The switch is not intended  
as an active multiplexer. Switch-  
ing while high voltages or cur-  
rents are present may cause  
instrument damage and lead to  
the risk of electric shock.  
34401A User’s Guide  
iii  
LO to Ground Protection Limit. The LO  
input terminal can safely "float" a maxi-  
mum of 500 Vpk relative to ground.  
WARNING  
IEC Measurement Category II. The  
HI and LO input terminals may be  
connected to mains in IEC Cate-  
gory II installations for line volt-  
ages up to 300 VAC. To avoid the  
danger of electric shock, do not  
connect the inputs to mains for  
line voltages above 300 VAC. See  
"IEC Measurement Category II  
Overvoltage Protection" on the  
following page for further infor-  
mation.  
As is implied by the above limits, the Protec-  
tion Limit for the HI input terminal is a maxi-  
mum of 1500 Vpk relative to ground.  
Current Input Terminal. The current input  
("I") terminal has a Protection Limit of 3A  
(rms) maximum current flowing from the LO  
input terminal. Note that the current input  
terminal will be at approximately the same  
voltage as the LO terminal.  
Note: The current-protection circuitry  
includes a fuse on the rear panel. To main-  
tain protection, replace this fuse only with a  
fuse of the specified type and rating.  
Sense Terminal Protection  
Limits  
WARNING  
The HI and LO sense terminals are used  
only for four-wire resistance and tempera-  
ture measurements ("4W"). The Protec-  
tion Limit is 200 Vpk for all of the terminal  
pairings:  
Protection Limits: To avoid instru-  
ment damage and the risk of elec-  
tric shock, do not exceed any of  
the Protection Limits defined in  
the following section.  
Note: The front-panel terminals are shown  
above. The rear-panel terminals are identi-  
cal. The Front/Rear switch selects the ter-  
minal set to be used. Do not operate this  
switch while signals are present on the  
front or rear terminals. The current-protec-  
tion fuse is on the rear panel.  
LO sense to LO input  
HI sense to LO input  
HI sense to LO sense  
Protection Limits  
Note: The 200 Vpk limit on the sense termi-  
nals is the Protection Limit. Operational  
voltages in resistance measurements are  
much lower — less than 10 V in normal  
operation.  
The Agilent 34401A Digital Multimeter pro-  
vides protection circuitry to prevent damage  
to the instrument and to protect against the  
danger of electric shock, provided the Pro-  
tection Limits are not exceeded. To ensure  
safe operation of the instrument, do not  
exceed the Protection Limits shown on the  
front and rear panel, and defined as follows:  
Input Terminal Protection  
Limits  
Protection Limits are defined for the input  
terminals:  
IEC Measurement Category II  
Overvoltage Protection  
Main Input (HI and LO) Terminals. The HI  
and LO input terminals are used for voltage,  
resistance, frequency (period), and diode  
test measurements. Two Protection Limits  
are defined for these terminals:  
To protect against the danger of electric  
shock, the Agilent 34401A Digital Multime-  
ter provides overvoltage protection for  
line-voltage mains connections meeting  
both of the following conditions:  
HI to LO Protection Limit. The Protection  
Limit from HI to LO (Input terminals) is  
1000 VDC or 750 VAC, which is also the  
maximum voltage measurement. This  
limit can also be expressed as 1000 Vpk  
maximum.  
The HI and LO input terminals are con-  
nected to the mains under Measurement  
Category II conditions, defined below,  
and  
The mains are limited to a maximum line  
voltage of 300 VAC.  
iv  
34401A User’s Guide  
IEC Measurement Category II includes elec-  
trical devices connected to mains at an out-  
let on a branch circuit. Such devices include  
most small appliances, test equipment, and  
other devices that plug into a branch outlet  
or socket. The 34401A may be used to make  
measurements with the HI and LO inputs  
connected to mains in such devices, or to  
the branch outlet itself (up to 300 VAC).  
However, the 34401A may not be used with  
its HI and LO inputs connected to mains in  
permanently installed electrical devices  
such as the main circuit-breaker panel,  
sub-panel disconnect boxes, or permanently  
wired motors. Such devices and circuits are  
subject to overvoltages that may exceed the  
protection limits of the 34401A.  
Agilent 34138A Test Lead Set  
Additional Notices  
The Agilent 34401A is compatible with the  
Agilent 34138A Test Lead Set described  
below.  
Waste Electrical and  
Electronic Equipment (WEEE)  
Directive 2002/96/EC  
Test Lead Ratings  
Test Leads - 1000V, 15A  
This product complies with the WEEE Direc-  
tive (2002/96/EC) marking requirement.  
The affixed product label (see below) indi-  
cates that you must not discard this electri-  
cal/electronic product in domestic  
household waste.  
Fine Tip Probe Attachments - 300V, 3A  
Mini Grabber Attachment - 300V, 3A  
SMT Grabber Attachments - 300V, 3A  
Operation  
Product Category: With reference to the  
equipment types in the WEEE directive  
Annex 1, this product is classified as a  
"Monitoring and Control instrumentation"  
product.  
The Fine Tip, Mini Grabber, and SMT Grab-  
ber attachments plug onto the probe end of  
the Test Leads.  
Maintenance  
Note: Voltages above 300 VAC may be mea-  
sured only in circuits that are isolated from  
mains. However, transient overvoltages are  
also present on circuits that are isolated  
from mains. The Agilent 34401A are  
designed to safely withstand occasional  
transient overvoltages up to 2500 Vpk. Do  
not use this equipment to measure circuits  
where transient overvoltages could exceed  
this level.  
If any portion of the Test Lead Set is worn or  
damaged, do not use. Replace with a new  
Agilent 34138A Test Lead Set.  
Do not dispose in domestic household  
waste.  
To return unwanted products, contact your  
local Agilent office, or see  
www.agilent.com/environment/product  
for more information.  
WARNING  
If the Test Lead Set is used in a  
manner not specified by Agilent  
Technologies, the protection pro-  
vided by the Test Lead Set may be  
impaired. Also, do not use a dam-  
aged or worn Test Lead Set.  
Instrument damage or personal  
injury may result.  
34401A User’s Guide  
v
DECLARATION OF CONFORMITY  
According to ISO/IEC Guide 22 and CEN/CENELEC EN 45014  
Manufacturer’s Name:  
Manufacturer’s Address:  
Agilent Technologies, Incorporated  
815 – 14th St. SW  
Loveland, Colorado 80537  
USA  
Declares, that the product  
Product Name:  
Model Number:  
Product Options:  
Multimeter  
34401A  
This declaration covers all options of the above product(s).  
Conforms with the following European Directives:  
The product herewith complies with the requirements of the Low Voltage Directive 73/23/EEC and the EMC Directive 89/336/EEC  
(including 93/68/EEC) and carries the CE Marking accordingly.  
Conforms with the following product standards:  
EMC  
Standard  
Limit  
IEC 61326-1:1997+A1:1998 / EN 61326-1:1997+A1:1998  
CISPR 11:1990 / EN 55011:1991  
Group 1 Class A  
IEC 61000-4-2:1995+A1:1998 / EN 61000-4-2:1995  
IEC 61000-4-3:1995 / EN 61000-4-3:1995  
IEC 61000-4-4:1995 / EN 61000-4-4:1995  
IEC 61000-4-5:1995 / EN 61000-4-5:1995  
IEC 61000-4-6:1996 / EN 61000-4-6:1996  
IEC 61000-4-11:1994 / EN 61000-4-11:1994  
4kV CD, 8kV AD  
3 V/m, 80-1000 MHz  
0.5kV signal lines, 1kV power lines  
0.5 kV line-line, 1 kV line-ground  
3V, 0.15-80 MHz  
Dips: 30% 10ms; 60% 100ms  
Interrupt > 95%@5000ms  
Canada: ICES-001:1998  
Australia/New Zealand: AS/NZS 2064.1  
The product was tested in a typical configuration with Agilent Technologies test systems.  
IEC 61010-1:1990+A1:1992+A2:1995 / EN 61010-1:1993+A2:1995  
Canada: CSA C22.2 No. 1010.1:1992  
UL 3111-1: 1994  
Safety  
18 July 2001  
Date  
Ray Corson  
Product Regulations Program Manager  
For further information, please contact your local Agilent Technologies sales office, agent or distributor.  
Authorized EU-representative: Agilent Technologies Deutschland GmbH, Herrenberger Strabe 130, D 71034 Böblingen, Germany  
Note: Unless otherwise indicated, this manual applies to all Serial Numbers.  
The Agilent Technologies 34401A is a 612-digit, high-performance  
digital multimeter. Its combination of bench-top and system features  
makes this multimeter a versatile solution for your measurement needs  
now and in the future.  
Con ven ien t Ben ch -Top F ea t u r es  
Highly visible vacuum-fluorescent display  
Built-in math operations  
Continuity and diode test functions  
Hands-free, Reading Hold feature  
Portable, ruggedized case with non-skid feet  
F lexible System F ea t u r es  
GPIB (IEEE-488) interface and RS-232 interface  
Standard programming languages: SCPI, Agilent 3478A, and  
Fluke 8840  
Reading rates up to 1000 readings per second  
Storage for up to 512 readings  
Limit testing with pass/fail signals  
Optional 34812A BenchLink/ Meter Software for Microsoft®  
TM  
Windows  
Agilent 34401A  
Multimeter  
The Front Panel at a Glance  
1 Measurement Function keys  
2 Math Operation keys  
3 Single Trigger / Autotrigger / Reading Hold key  
4 Shift / Local key  
5 Front / Rear Input Terminal Switch  
6 Range / Number of Digits Displayed keys  
7 Menu Operation keys  
2
The Front-Panel Menu at a Glance  
The menu is organized in a top-down tree structure with three levels.  
A: MEASurement MENU  
1: AC FILTER > 2: CONTINUITY > 3: INPUT R > 4: RATIO FUNC > 5: RESOLUTION  
B: MATH MENU  
1: MIN-MAX > 2: NULL VALUE > 3: dB REL > 4: dBm REF R > 5: LIMIT TEST > 6: HIGH LIMIT > 7: LOW LIMIT  
C: TRIGger MENU  
1: READ HOLD > 2: TRIG DELAY > 3: N SAMPLES  
D: SYStem MENU  
1: RDGS STORE > 2: SAVED RDGS > 3: ERROR > 4: TEST > 5: DISPLAY > 6: BEEP > 7: COMMA > 8: REVISION  
E: Input / Output MENU  
1: GPIB ADDR > 2: INTERFACE > 3: BAUD RATE > 4: PARITY > 5: LANGUAGE  
*
F: CALibration MENU  
1: SECURED > [ 1: UNSECURED ] > [ 2: CALIBRATE ] > 3: CAL COUNT > 4: MESSAGE  
The commands enclosed in square brackets ( [ ] ) are “hidden” unless the multimeter  
is UNSECURED for calibration.  
*
3
Display Annunciators  
Turns on during a measurement.  
Multimeter is addressed to listen or talk over the GPIB interface.  
Adrs  
Rmt  
Multimeter is in remote mode (remote interface).  
Multimeter is using manual ranging (autorange is disabled).  
Multimeter is waiting for a single trigger or external trigger.  
Reading Hold is enabled.  
Turns on when reading memory is enabled.  
Multimeter is in dcv:dcv ratio function.  
A math operation is enabled (null, min-max, dB, dBm, or limit test).  
Hardware or remote interface command errors are detected.  
Rear input terminals are selected.  
“Shift” key has been pressed. Press “Shift” again to turn off.  
Multimeter is in 4-wire ohms function.  
Man  
Trig  
Hold  
Mem  
Ratio  
Math  
ERROR  
Rear  
Shift  
4W  
Multimeter is in continuity test function.  
Multimeter is in diode test function.  
To review the display annunciators, hold down the Shift key as you  
turn on the multimeter.  
4
The Rear Panel at a Glance  
1
2
3
4
Chassis Ground  
5
6
7
8
Voltmeter Complete Output Terminal  
External Trigger Input Terminal  
GPIB (IEEE-488) Interface connector  
RS-232 interface connector  
Power-Line Fuse-Holder Assembly  
Power-Line Voltage Setting  
Front and Rear Current Input Fuse  
Use the front-panel Input / Output Menu to:  
Select the GPIB or RS-232 interface (see chapter 4).  
Set the GPIB bus address (see chapter 4).  
Set the RS-232 baud rate and parity (see chapter 4).  
5
In This Book  
Qu ick Sta r t Chapter 1 prepares the multimeter for use and helps you  
get familiar with a few of its front-panel features.  
F r on t-P a n el Men u Op er ation Chapter 2 introduces you to the  
front-panel menu and describes some of the multimeters menu features.  
F ea t u r es a n d F u n ct ion s Chapter 3 gives a detailed description of the  
multimeters capabilities and operation. You will find this chapter  
useful whether you are operating the multimeter from the front panel or  
over the remote interface.  
Rem ot e In t er fa ce Refer en ce Chapter 4 contains reference  
information to help you program the multimeter over the remote interface.  
E r r or Messa ges Chapter 5 lists the error messages that may appear  
as you are working with the multimeter. Each listing contains enough  
information to help you diagnose and solve the problem.  
App lica t ion P r ogr a m s Chapter 6 contains several remote interface  
application programs to help you develop programs for your  
measurement application.  
Mea su r em en t Tu tor ia l Chapter 7 discusses measurement  
considerations and techniques to help you obtain the best accuracies  
and reduce sources of measurement error.  
Sp ecifica t ion s Chapter 8 lists the multimeters specifications and  
describes how to interpret these specifications.  
If you have questions relating to the operation of the Agilent 34401A,  
call 1-800-452-4844 in the United States, or contact your nearest  
Agilent Sales Office.  
If your 34401A fails within one year of purchase, Agilent will repair or  
replace it free of charge. Call 1-877-444-7278 (Agilent Express) in the  
United States, or contact your nearest Agilent Sales Office.  
6
Contents  
Ch a p t er 1 Qu ick St a r t  
To Prepare the Multimeter for Use 13  
If the Multimeter Does Not Turn On 14  
To Adjust the Carrying Handle 16  
To Measure Voltage 17  
To Measure Resistance 17  
To Measure Current 18  
To Measure Frequency (or Period) 18  
To Test Continuity 19  
To Check Diodes 19  
To Select a Range 20  
To Set the Resolution 21  
Front-Panel Display Formats 22  
To Rack Mount the Multimeter 23  
Ch a p t er 2 F r on t-P a n el Men u Op er a t ion  
Front-Panel Menu Reference 27  
A Front-Panel Menu Tutorial 29  
To Turn Off the Comma Separator 37  
To Make Null (Relative) Measurements 38  
To Store Minimum and Maximum Readings 39  
To Make dB Measurements 40  
To Make dBm Measurements 41  
To Trigger the Multimeter 42  
To Use Reading Hold 43  
To Make dcv:dcv Ratio Measurements 44  
To Use Reading Memory 46  
Ch a p ter 3 F ea tu r es a n d F u n ction s  
Measurement Configuration  
AC Signal Filter 51  
Continuity Threshold Resistance 52  
DC Input Resistance 53  
Resolution 54  
Integration Time 57  
Front / Rear Input Terminal Switching 58  
Autozero 59  
Ranging 60  
7
Contents  
Ch a p ter 3 F ea tu r es a n d F u n ction s (continued)  
Math Operations  
Min-Max Operation 64  
Null (Relative) Operation 65  
dB Measurements 67  
dBm Measurements 68  
Limit Testing 69  
Triggering  
Trigger Source Choices 73  
The Wait-for-Trigger State 76  
Halting a Measurement in Progress 76  
Number of Samples 77  
Number of Triggers 78  
Trigger Delay 79  
Automatic Trigger Delays 81  
Reading Hold 82  
Voltmeter Complete Terminal 83  
External Trigger Terminal 83  
System-Related Operations  
Reading Memory 84  
Error Conditions 85  
Self-Test 86  
Display Control 87  
Beeper Control 88  
Comma Separators 89  
Firmware Revision Query 89  
SCPI Language Version Query 90  
Remote Interface Configuration  
GPIB Address 91  
Remote Interface Selection 92  
Baud Rate Selection (RS-232) 93  
Parity Selection (RS-232) 93  
Programming Language Selection 94  
Calibration  
Calibration Security 95  
Calibration Count 98  
Calibration Message 99  
Operator Maintenance  
To Replace the Power-Line Fuse 100  
To Replace the Current Input Fuses 100  
Power-On and Reset State 101  
8
Contents  
Ch a p t er 4 Rem ot e In t er fa ce Refer en ce  
Command Summary 105  
Simplified Programming Overview 112  
The MEASure? and CONFigure Commands 117  
Measurement Configuration Commands 121  
Math Operation Commands 124  
Triggering 127  
Triggering Commands 130  
System-Related Commands 132  
The SCPI Status Model 134  
Status Reporting Commands 144  
Calibration Commands 146  
RS-232 Interface Configuration 148  
RS-232 Interface Commands 153  
An Introduction to the SCPI Language 154  
Output Data Formats 159  
Using Device Clear to Halt Measurements 160  
TALK ONLY for Printers 160  
To Set the GPIB Address 161  
To Select the Remote Interface 162  
To Set the Baud Rate 163  
To Set the Parity 164  
To Select the Programming Language 165  
Alternate Programming Language Compatibility 166  
SCPI Compliance Information 168  
IEEE-488 Compliance Information 169  
Ch a p t er 5 E r r or Messa ges  
Execution Errors 173  
Self-Test Errors 179  
Calibration Errors 180  
Ch a p t er 6 Ap plica t ion P r ogr a m s  
Using MEASure? for a Single Measurement 185  
Using CONFigure with a Math Operation 186  
Using the Status Registers 188  
RS-232 Operation Using QuickBASIC 192  
RS-232 Operation Using Turbo C 193  
9
Contents  
Ch a p t er 7 Mea su r em en t Tu t or ia l  
Thermal EMF Errors 199  
Loading Errors (dc volts) 199  
Leakage Current Errors 199  
Rejecting Power-Line Noise Voltages 200  
Common Mode Rejection (CMR) 201  
Noise Caused by Magnetic Loops 201  
Noise Caused by Ground Loops 202  
Resistance Measurements 203  
4-Wire Ohms Measurements 203  
Removing Test Lead Resistance Errors 204  
Power Dissipation Effects 204  
Settling Time Effects 204  
Errors in High Resistance Measurements 205  
DC Current Measurement Errors 205  
True RMS AC Measurements 206  
Crest Factor Errors 207  
Loading Errors (ac volts) 209  
Measurements Below Full Scale 210  
High-Voltage Self-Heating Errors 210  
Temperature Coefficient and Overload Errors 210  
Low-Level Measurement Errors 211  
Common Mode Errors 212  
AC Current Measurement Errors 212  
Frequency and Period Measurement Errors 213  
Making High-Speed DC and Resistance Measurements 213  
Making High-Speed AC Measurements 214  
Ch a p t er 8 Sp ecifica tion s  
DC Characteristics 216  
AC Characteristics 218  
Frequency and Period Characteristics 220  
General Information 222  
Product Dimensions 223  
To Calculate Total Measurement Error 224  
Interpreting Multimeter Specifications 226  
Configuring for Highest Accuracy Measurements 229  
In d ex 231  
Decla r a t ion of Con for m it y 237  
10  
1
1
Quick Start  
Quick Start  
One of the first things you will want to do with your multimeter is to  
become acquainted with its front panel. We have written the exercises  
in this chapter to prepare the multimeter for use and help you get  
familiar with some of its front-panel operations.  
The front panel has two rows of keys to select various functions and  
operations. Most keys have a shifted function printed in blue above  
the key. To perform a shifted function, press Shift (the Shift  
annunciator will turn on). Then, press the key that has the desired  
label above it. For example, to select the dc current function,  
press Shift DC V .  
If you accidentally press Shift , just press it again to turn off the  
Shift annunciator.  
The rear cover of this book is a fold-out Quick Reference Guide. On this  
cover you will find a quick summary of various multimeter features.  
12  
Chapter 1 Quick Start  
To Prepare the Multimeter for Use  
1
To Prepare the Multimeter for Use  
The following steps help you verify that the multimeter is ready for use.  
1 Ch eck th e list of su p p lied item s.  
Verify that you have received the following items with your multimeter.  
If anything is missing, contact your nearest Agilent Sales Office.  
One test lead kit.  
One power cord.  
This Users Guide.  
One Service Guide.  
One folded Quick Reference card.  
Certificate of Calibration.  
2 Con n ect th e pow er cor d a n d tu r n on th e m u ltim eter .  
The front-panel display will light up while the multimeter performs its  
power-on self-test. The GPIB bus address is displayed. Notice that the  
multimeter powers up in the dc voltage function with autoranging enabled.  
To review the power-on display with all annunciators turned on,  
hold down Shift as you turn on the multimeter.  
3 P er for m a com plete self-test.  
The complete self-test performs a more extensive series of tests than  
those performed at power-on. Hold down Shift as you press the  
Power switch to turn on the multimeter; hold down the key for more  
than 5 seconds. The self-test will begin when you release the key.  
If the self-test is successful, PASS” is displayed. If the self-test is  
not successful, FAIL” is displayed and the ERROR annunciator turns on.  
See the Service Guide for instructions on returning the multimeter to  
Agilent for service.  
13  
Chapter 1 Quick Start  
If the Multimeter Does Not Turn On  
1
If the Multimeter Does Not Turn On  
Use the following steps to help solve problems you might encounter  
when turning on the multimeter. If you need more help, see the  
Service Guide for instructions on returning the multimeter to Agilent for  
service.  
1 Ver ify t h a t t h er e is a c p ow er t o th e m u lt im et er .  
First, verify that the multimeters Power switch is in the On” position.  
Also, make sure that the power cord is firmly plugged into the power  
module on the rear panel. You should also make sure that the power  
source you plugged the multimeter into is energized.  
2 Ver ify t h e p ow er -lin e volta ge set tin g.  
The line voltage is set to the proper value for your country when the  
multimeter is shipped from the factory. Change the voltage setting if  
it is not correct. The settings are: 100, 120, 220, or 240 Vac (for 230 Vac  
operation, use the 220 Vac setting).  
See the next page if you need to change the line-voltage setting.  
3 Ver ify t h a t t h e p ow er -lin e fu se is good .  
The multimeter is shipped from the factory with a 250 mA fuse  
installed. This is the correct fuse for all line voltages.  
See the next page if you need to replace the power-line fuse.  
To replace the 250 mAT fuse, order Agilent part number 2110-0817.  
14  
Chapter 1 Quick Start  
If the Multimeter Does Not Turn On  
1
1 Rem ove th e power cor d. Remove the  
2 Remove the line-voltage selector from  
fuse-holder assembly from the rear panel.  
the assembly.  
See rear panel for proper fuse rating.  
Agilent Part Number: 2110-0817 (250 mAT)  
3 Rotate the line-voltage selector until the  
4 Replace the fuse-holder assembly in  
correct voltage appears in the window.  
the rear panel.  
100, 120, 220 (230) or 240 Vac  
Verify that the correct line voltage is selected and the power-line fuse is good.  
15  
Chapter 1 Quick Start  
To Adjust the Carrying Handle  
To Adjust the Carrying Handle  
To adjust the position, grasp the handle by the sides and pull outward.  
Then, rotate the handle to the desired position.  
Bench-top viewing positions  
Carrying position  
16  
Chapter 1 Quick Start  
To Measure Voltage  
1
To Measure Voltage  
Ranges: 100 mV, 1 V, 10 V, 100 V, 1000 V (750 Vac)  
Maximum resolution: 100 nV (on 100 mV range)  
AC technique: true RMS, ac-coupled  
To Measure Resistance  
Ranges: 100 Ω, 1 k, 10 k, 100 k, 1 M, 10 M, 100 MΩ  
Maximum resolution: 100 µΩ (on 100 ohm range)  
17  
Chapter 1 Quick Start  
To Measure Current  
To Measure Current  
Ranges: 10 mA (dc only), 100 mA (dc only), 1 A , 3 A  
Maximum resolution: 10 nA (on 10 mA range)  
AC technique: true RMS, ac-coupled  
To Measure Frequency (or Period)  
Measurement band: 3 Hz to 300 kHz (0.33 sec to 3.3 µsec)  
Input signal range: 100 mVac to 750 Vac  
Technique: reciprocal counting  
18  
Chapter 1 Quick Start  
To Test Continuity  
1
To Test Continuity  
Test current source: 1 mA  
Maximum resolution: 0.1 (range is fixed at 1 kohm)  
Beeper threshold: 1 to 1000 (beeps below adjustable threshold)  
To Check Diodes  
Test current source: 1 mA  
Maximum resolution: 100 µV (range is fixed at 1 Vdc)  
Beeper threshold: 0.3 volts Vmeasured 0.8 volts (not adjustable)  
19  
Chapter 1 Quick Start  
To Select a Range  
To Select a Range  
You can let the multimeter automatically select the range using  
autoranging or you can select a fixed range using manual ranging.  
Selects a lower range and  
disables autoranging.  
Selects a higher range and  
disables autoranging.  
Man annunciator is on when  
manual range is enabled.  
Toggles between autoranging  
and manual ranging.  
Autoranging is selected at power-on and after a remote interface reset.  
Autorange thresholds:  
Down range at <10% of range  
Up range at >120% of range  
If the input signal is greater than the present range can measure,  
the multimeter will give an overload indication (OVLD).  
For frequency and period measurements from the front panel,  
ranging applies to the signals input voltage, not its frequency.  
The range is fixed for continuity (1 krange) and diode (1 Vdc range).  
Ranging is local to the selected function. This means that you can select  
the ranging method (auto or manual) for each function independently.  
When manually ranging, the selected range is local to the function;  
the multimeter remembers the range when you switch between functions.  
20  
Chapter 1 Quick Start  
To Set the Resolution  
1
To Set the Resolution  
You can set the display resolution to 412, 512, or 612 digits either to  
optimize measurement speed or noise rejection. In this book, the most  
significant digit (leftmost on the display) is referred to as the 12” digit,  
since it can only be a 0 or 1.”  
Press the Shift key.  
Selects 412 digits.  
Selects 512 digits.  
Selects 612 digits (most noise rejection).  
The resolution is set to 512 digits at power-on and after a remote  
interface reset.  
The resolution is fixed at 512 digits for continuity and diode tests.  
You can also vary the number of digits displayed using the arrow keys  
(however, the integration time is not changed).  
Fewer  
Digits  
More  
Digits  
Resolution is local to the selected function. This means that you can  
select the resolution for each function independently. The multimeter  
remembers the resolution when you switch between functions.  
21  
Chapter 1 Quick Start  
Front-Panel Display Formats  
Front-Panel Display Formats  
H
D
Negative sign or blank (positive)  
12 ” digit (0 or 1)  
Numeric digits  
-H.DDD,DDD EFFF  
E
Exponent ( m, k, M )  
F
Measurement units ( VDC, OHM, HZ, dB )  
Front-panel display format.  
5 digits  
10.216,5 VDC  
12” digit  
This is the 10 Vdc range, 512 digits are displayed.  
12” digit  
-045.23  
mVDC  
This is the 100 mVdc range, 412 digits are displayed.  
113.325,6 OHM  
This is the 100 ohm range, 612 digits are displayed.  
OVL.D  
mVDC  
This is an overload indication on the 100 mVdc range.  
22  
Chapter 1 Quick Start  
To Rack Mount the Multimeter  
1
To Rack Mount the Multimeter  
You can mount the multimeter in a standard 19-inch rack cabinet using  
one of three optional kits available. Instructions and mounting hardware  
are included with each rack-mounting kit. Any Agilent System II  
instrument of the same size can be rack-mounted beside the 34401A.  
Remove the carrying handle, and the front and rear rubber bumpers,  
before rack-mounting the multimeter.  
To remove the handle, rotate it to the vertical position and pull the ends outward.  
Front  
Rear (bottom view)  
To remove the rubber bumper, stretch a corner and then slide it off.  
23  
Chapter 1 Quick Start  
To Rack Mount the Multimeter  
To rack mount a single instrument, order adapter kit 5063-9240.  
To rack mount two instruments side-by-side, order lock-link kit 5061-9694 and  
flange kit 5063-9212.  
To install one or two instruments in a sliding support shelf, order shelf 5063-9255,  
and slide kit 1494-0015 (for a single instrument, also order filler panel 5002-3999).  
24  
2
2
Front-Panel  
Menu Operation  
Front-Panel Menu Operation  
By now you should be familiar with the FUNCTION and RANGE / DIGITS  
groups of front-panel keys. You should also understand how to make  
front-panel connections for the various types of measurements. If you  
are not familiar with this information, we recommend that you read  
chapter 1, Quick Start,” starting on page 11.  
This chapter introduces you to three new groups of front-panel keys:  
MENU, MATH, and TRIG. You will also learn how to use the comma  
separator and store readings in memory. This chapter does not give a  
detailed description of every front-panel key or menu operation. It does,  
however, give you a good overview of the front-panel menu and many  
front-panel operations. See chapter 3 Features and Functions,” starting  
on page 49, for a complete discussion of the multimeters capabilities  
and operation.  
26  
Chapter 2 Front-Panel Menu Operation  
Front-Panel Menu Reference  
Front-Panel Menu Reference  
2
A: MEASurement MENU  
1: AC FILTER > 2: CONTINUITY > 3: INPUT R > 4: RATIO FUNC > 5: RESOLUTION  
1: AC FILTER  
2: CONTINUITY  
3: INPUT R  
4: RATIO FUNC  
5: RESOLUTION  
Selects the slow, medium, or fast ac filter.  
Sets the continuity beeper threshold (1 to 1000 ).  
Sets the input resistance for dc voltage measurements.  
Enables the dcv:dcv ratio function.  
Selects the measurement resolution.  
B: MATH MENU  
1: MIN-MAX > 2: NULL VALUE > 3: dB REL > 4: dBm REF R > 5: LIMIT TEST > 6: HIGH LIMIT > 7: LOW LIMIT  
1: MIN-MAX  
2: NULL VALUE  
3: dB REL  
4: dBm REF R  
5: LIMIT TEST  
6: HIGH LIMIT  
7: LOW LIMIT  
Recalls the stored minimum, maximum, average, and reading count.  
Recalls or sets the null value stored in the null register.  
Recalls or sets the dBm value stored in the dB relative register.  
Selects the dBm reference resistance value.  
Enables or disables limit testing.  
Sets the upper limit for limit testing.  
Sets the lower limit for limit testing.  
C: TRIGger MENU  
1: READ HOLD > 2: TRIG DELAY > 3: N SAMPLES  
1: READ HOLD  
2: TRIG DELAY  
3: N SAMPLES  
Sets the reading hold sensitivity band.  
Specifies a time interval which is inserted before a measurement.  
Sets the number of samples per trigger.  
27  
Chapter 2 Front-Panel Menu Operation  
Front-Panel Menu Reference  
D: SYStem MENU  
1: RDGS STORE > 2: SAVED RDGS > 3: ERROR > 4: TEST > 5: DISPLAY > 6: BEEP > 7: COMMA > 8: REVISION  
1: RDGS STORE  
2: SAVED RDGS  
3: ERROR  
Enables or disables reading memory.  
Recalls readings stored in memory (up to 512 readings).  
Retrieves errors from the error queue (up to 20 errors).  
Performs a complete self-test.  
4: TEST  
5: DISPLAY  
6: BEEP  
Enables or disables the front-panel display.  
Enables or disables the beeper function.  
7: COMMA  
8: REVISION  
Enables or disables a comma separator between digits on the display.  
Displays the multimeter’s firmware revision codes.  
E: Input / Output MENU  
1: GPIB ADDR > 2: INTERFACE > 3: BAUD RATE > 4: PARITY > 5: LANGUAGE  
1: HP-IB ADDR  
2: INTERFACE  
3: BAUD RATE  
4: PARITY  
Sets the GPIB bus address (0 to 31).  
Selects the GPIB or RS-232 interface.  
Selects the baud rate for RS-232 operation.  
Selects even, odd, or no parity for RS-232 operation.  
Selects the interface language: SCPI, Agilent 3478, or Fluke  
8840/42.  
5: LANGUAGE  
*
F: CALibration MENU  
1: SECURED > [ 1: UNSECURED ] > [ 2: CALIBRATE ] > 3: CAL COUNT > 4: MESSAGE  
1: SECURED  
The multimeter is secured against calibration; enter code to unsecure.  
1: UNSECURED  
2: CALIBRATE  
3: CAL COUNT  
4: MESSAGE  
The multimeter is unsecured for calibration; enter code to secure.  
Performs complete calibration of present function; must be UNSECURED.  
Reads the total number of times the multimeter has been calibrated.  
Reads the calibration string (up to 12 characters) entered from remote.  
The commands enclosed in square brackets ( [ ] ) are “hidden” unless the multimeter is UNSECURED for calibration.  
*
28  
Chapter 2 Front-Panel Menu Operation  
A Front-Panel Menu Tutorial  
A Front-Panel Menu Tutorial  
This section is a step-by-step tutorial which shows how to use the  
front-panel menu. We recommend that you spend a few minutes with this  
tutorial to get comfortable with the structure and operation of the menu.  
2
The menu is organized in a top-down tree structure with three  
levels (menus, commands, and parameters). You move down  
or up  
the menu tree to get from one level to the next. Each of the  
three levels has several horizontal choices which you can view by  
moving left  
<
or right > .  
Menus  
Commands  
Parameters  
To turn on the menu, press Shift Menu On/Off  
.
To turn off the menu, press Shift Menu On/Off , or press any of  
the function or math keys on the top row of front-panel keys.  
To execute a menu command, press Enter .  
To recall the last menu command that was executed,  
press Shift Recall  
.
29  
Chapter 2 Front-Panel Menu Operation  
A Front-Panel Menu Tutorial  
MESSAGES DISPLAYED DURING MENU USE  
TOP OF MENU You pressed  
the menu and you cannot go any higher.  
while on the “menus” level; this is the top level of  
Shift  
<
To turn off the menu, press  
on a level, press or  
(Menu On/Off). To move across the choices  
. To move down a level, press  
.
<
>
<
>
MENUS You are on the “menus” level. Press  
or  
to view the choices.  
<
<
>
>
COMMANDS You are on the “commands” level. Press  
command choices within the selected menu group.  
or  
or  
to view the  
PARAMETER You are on the “parameter” level. Press  
the parameter for the selected command.  
to view and edit  
MENU BOTTOM You pressed  
level of the menu and you cannot go any lower.  
while on the “parameter” level; this is the bottom  
<
Shift  
To turn off the menu, press  
press  
(Menu On/Off). To move up a level,  
.
CHANGE SAVED The change made on the “parameter” level is saved. This is  
displayed after you press (Menu Enter) to execute the command.  
Auto/Man  
MIN VALUE The value you specified on the “parameter” level is too small for the  
selected command. The minimum value allowed is displayed for you to edit.  
MAX VALUE The value you specified on the “parameter” level is too large for the  
selected command. The maximum value allowed is displayed for you to edit.  
EXITING MENU You will see this message if you turn off the menu by pressing  
Shift  
<
(Menu On/Off) or a front-panel function/math key. You did not edit any values  
on the “parameter” level and changes were NOT saved.  
NOT ENTERED You will see this message if you turn off the menu by pressing  
(Menu On/Off) or a front-panel function/math key. You did some editing of  
<
Shift  
parameters but the changes were NOT saved.  
to save changes made on the “parameter” level.  
Press  
(Menu Enter)  
Auto/Man  
NOT RELEVANT The selected math operation is NOT valid for the function in use.  
30  
Chapter 2 Front-Panel Menu Operation  
A Front-Panel Menu Tutorial  
Menu Example 1  
The following steps show you how to turn on the menu, move up or  
down between levels, move across the choices on each level, and turn off  
the menu. In this example, you will turn off the front-panel beeper.  
On/Off  
2
Shift  
<
1 Tu r n on t h e m en u .  
You enter the menu on the menus” level. The MEAS MENU is your first  
choice on this level.  
A: MEAS MENU  
>
>
>
2 Move a cr oss t o t h e SYS MENU ch oice on th is level.  
There are six menu group choices available on the menus” level. Each  
choice has a letter prefix for easy identification (A: , B: , etc.).  
D: SYS MENU  
3 Move d ow n t o t h e com m a n ds” level w ith in t h e SYS MENU.  
The RDGS STORE command is your first choice on this level.  
1: RDGS STORE  
31  
Chapter 2 Front-Panel Menu Operation  
A Front-Panel Menu Tutorial  
>
>
>
>
>
4 Move a cr oss t o t h e BEEP com m a n d on t h e com m a n d s” level.  
There are eight command choices available in the SYS MENU. Each  
choice on this level has a number prefix for easy identification (1: , 2: , etc.).  
6: BEEP  
5 Move d ow n a level to t h e BEE P pa r am et er ch oices.  
The first parameter choice is ON” for the BEEP command (the beeper  
setting is stored in non-volatile memory and ON” is the factory setting).  
ON  
>
6 Move a cr oss t o t h e OF F ” ch oice.  
There are two parameter choices for BEEP.  
OFF  
Auto/Man  
ENTER  
7 Sa ve t h e ch a n ge a n d t u r n off t h e m en u .  
The multimeter beeps and displays a message to show that the change  
is now in effect. You are then exited from the menu.  
CHANGE SAVED  
32  
Chapter 2 Front-Panel Menu Operation  
A Front-Panel Menu Tutorial  
Menu Example 2  
The following exercise demonstrates how to use the menu recall feature  
as a shortcut to set the BEEP command back to its original setting.  
You must perform the steps in Example 1 before you start this example.  
Recall  
2
>
Shift  
1 Use m en u r eca ll to r etu r n to th e BEE P com m a n d.  
This returns you to the BEEP command, which was the last command  
used before you exited the menu in the Example 1.  
6: BEEP  
2 Move d ow n to th e BEEP p a r a m eter ch oices.  
The first parameter choice is OFF” (the current setting from Example 1).  
OFF  
>
3 Move a cr oss t o t h e ON” ch oice.  
Set the parameter back to its original value.  
ON  
Auto/Man  
ENTER  
4 Sa ve t h e ch a n ge a n d t u r n off t h e m en u .  
The multimeter beeps and displays a message to show that the change  
is now in effect. You are then exited from the menu.  
CHANGE SAVED  
33  
Chapter 2 Front-Panel Menu Operation  
A Front-Panel Menu Tutorial  
Menu Example 3  
Some commands in the menu require that you enter a numeric  
parameter value. The following steps show you how to enter a number  
in the menu. For this example, you will set the null value to –2.0 volts.  
Make sure the multimeter is in the dc voltage function with 512 digits of  
resolution displayed. Disconnect all inputs to the multimeter.  
On/Off  
Shift  
<
1 Tu r n on t h e m en u .  
You enter the menu on the menus” level. The MEAS MENU is your first  
choice on this level.  
A: MEAS MENU  
>
2 Move a cr oss t o t h e MATH MENU ch oice on t h is level.  
There are six menu group choices available on this level.  
B: MATH MENU  
3 Move d ow n t o t h e com m a n ds” level w ith in t h e MATH MENU.  
The MIN–MAX command is your first choice on this level.  
1: MIN-MAX  
>
4 Move a cr oss t o t h e NULL VALUE com m a n d on th is level.  
There are seven command choices available within the MATH MENU.  
2: NULL VALUE  
34  
Chapter 2 Front-Panel Menu Operation  
A Front-Panel Menu Tutorial  
5 Move d ow n to edit th e NULL VALUE p a r a m et er .  
The null value should be 0.0 Vdc when you come to this point in the  
menu for the first time. For this example, you will set the null value  
to 2.0 volts.  
2
000.000 mVDC  
When you see the flashing ” on the left side of the display, you can  
abort the edit and return to the commands” level by pressing  
.  
6 Ma k e th e n u m ber n ega tive.  
The leftmost character on the display toggles between + and .  
-000.000 mVDC  
>
7 Move t h e fla sh in g cu r sor over t o edit t h e fir st d igit .  
Notice that the leftmost digit is flashing.  
-000.000 mVDC  
8 In cr em en t th e fir st digit u n til “2 ” is d ispla yed .  
You decrement or increment each digit independently. Neighboring  
digits are not affected.  
-200.000 mVDC  
35  
Chapter 2 Front-Panel Menu Operation  
A Front-Panel Menu Tutorial  
<
<
9 Move t h e fla sh in g cu r sor over t o t h e u n it s” loca t ion .  
Notice that the units are flashing on the right side of the display.  
-200.000 mVDC  
10 In cr ea se th e d isp la yed n u m ber by a fa ctor of 10.  
Notice that the position of the decimal point changes and the displayed  
number increases by a factor of 10.  
-2.000,00 VDC  
Auto/Man  
ENTER  
11 Sa ve t h e ch a n ge a n d t u r n off t h e m en u .  
The multimeter beeps and displays a message to show that the change  
is now in effect. You are then exited from the menu.  
CHANGE SAVED  
Keep in mind that math null is turned on and 2.0 volts is used as  
the null value for measurements. To clear the null value, press Null .  
This is the end of the front-panel menu tutorial. The remainder of the  
chapter discusses several of the most common front-panel operations.  
36  
Chapter 2 Front-Panel Menu Operation  
To Turn Off the Comma Separator  
To Turn Off the Comma Separator  
The multimeter can display readings on the front panel with or without  
a comma separator. The following steps show how to disable the comma.  
2
08.241,53 VDC  
08.24153 VDC  
With comma separator (factory setting)  
Without comma separator  
On/Off  
Shift  
<
1 Tu r n on t h e m en u .  
A: MEAS MENU  
>
>
>
2 Move a cr oss t o t h e SYS MENU ch oice on th e m en u s” level.  
D: SYS MENU  
<
>
<
3 Move d ow n a level a n d t h en a cr oss t o t h e COMMA com m a n d.  
7: COMMA  
4
Move d ow n a level a n d t h en m ove a cr oss t o t h e OF F ch oice.  
OFF  
Auto/Man  
ENTER  
5 Sa ve t h e ch a n ge a n d t u r n off t h e m en u .  
The comma separator setting is stored in non-volatile memory, and  
does not change when power has been off or after a remote interface reset.  
37  
Chapter 2 Front-Panel Menu Operation  
To Make Null (Relative) Measurements  
To Make Null (Relative) Measurements  
Each null measurement, also called relative, is the difference between a  
stored null value and the input signal.  
Resu lt = reading null value  
To read / edit the null value, use the MATH menu.  
Enables null operation;  
Press again to disable.  
Math annunciator is on when  
null operation is enabled.  
You can make null measurements with any function except  
continuity, diode, or ratio. The null operation is local to the selected  
function; when you change functions, null is disabled.  
To null the test lead resistance for more accurate two-wire ohms  
measurements, short the ends of the test leads together and then  
press Null .  
The first reading taken after you press Null is stored as the null  
value in the Null Register. Any previously stored value is  
replaced with the new value.  
After enabling null, you can edit the stored null value by  
pressing Shift > (Menu Recall). This takes you to the  
NULL VALUE” command in the MATH MENU (only if null is  
enabled). Go down to the parameter” level, and then edit the  
displayed value.  
The null register is cleared when you change functions, turn null off,  
turn off the power, or perform a remote interface reset.  
38  
Chapter 2 Front-Panel Menu Operation  
To Store Minimum and Maximum Readings  
To Store Minimum and Maximum Readings  
You can store the minimum and maximum readings during a series  
of measurements. The following discussion shows how to read the  
minimum, maximum, average, and reading count.  
2
To read the minimum, maximum, average, and count,  
use the MATH menu.  
Enables min-max operation;  
Press again to disable.  
Math annunciator is on when  
min-max operation is enabled.  
You can use min-max with any function except continuity or diode test.  
The min-max operation is local to the selected function; when you  
change functions, min-max is disabled.  
After enabling min-max, you can read the stored minimum,  
maximum, average, and count by pressing Shift  
>
(Menu Recall).  
This takes you to the MIN–MAX” command in the MATH MENU  
(only if min-max is enabled). Go down to the parameter” level,  
and then read the values by pressing < or > .  
The stored values are cleared when you turn min-max off, turn off the  
power, or perform a remote interface reset.  
The average is of all readings taken since min-max was enabled (not  
just the average of the stored minimum and maximum). The count is  
the total number of readings taken since min-max was enabled.  
39  
Chapter 2 Front-Panel Menu Operation  
To Make dB Measurements  
To Make dB Measurements  
Each dB measurement is the difference between the input signal and a  
stored relative value, with both values converted to dBm.  
d B = reading in dBm relative value in dBm  
To read / edit the dB relative value, use the MATH menu.  
Enables dB operation;  
Press again to disable.  
Math annunciator is on when  
dB operation is enabled.  
Select DC V or AC V .  
The first reading taken after you enable dB measurements is  
converted to dBm and is stored as the relative value in the  
dB Relative Register. Any previously stored value is replaced  
with the new value.  
After enabling dB operations, you can edit the relative value by  
pressing Shift  
>
(Menu Recall). This takes you to the dB REL”  
command in the MATH MENU (only if dB is enabled). Go down to  
the parameter” level, and then edit the value displayed.  
The register is cleared when you change functions, turn dB off,  
turn off the power, or perform a remote interface reset.  
40  
Chapter 2 Front-Panel Menu Operation  
To Make dBm Measurements  
To Make dBm Measurements  
The dBm operation calculates the power delivered to a resistance  
referenced to 1 milliwatt.  
2
d Bm = 10 × Log10 ( reading2 / reference resistance / 1 mW )  
To read / edit the dBm reference resistance,  
use the MATH menu.  
Enables dBm operation;  
Press again to disable.  
Math annunciator is on when  
dBm operation is enabled.  
Select DC V or AC V .  
The factory setting for the reference resistance is 600 . To select a  
different value, press Shift > (Menu Recall) after enabling dBm  
operations. This takes you to the dBm REF R” command in the  
MATH MENU (only if dBm is enabled).  
Go down to the parameter” level, and then select a value: 50, 75,  
93, 110, 124, 125, 135, 150, 250, 300, 500, 600, 800, 900, 1000,  
1200, or 8000 ohms.  
The reference resistance is stored in non-volatile memory, and does not  
change when power has been off or after a remote interface reset.  
41  
Chapter 2 Front-Panel Menu Operation  
To Trigger the Multimeter  
To Trigger the Multimeter  
You can trigger the multimeter from the front panel using single trigger  
or auto trigger.  
Enables single trigger  
and triggers the multimeter.  
(sample) annunciator is on  
during each measurement.  
Toggles between auto trigger  
and reading hold.  
Trig annunciator is on when the  
multimeter is waiting for single  
trigger (auto trigger disabled).  
Auto triggering is enabled when you turn on the multimeter. Notice  
that the (sample) annunciator turns on during each measurement.  
Single triggering takes one reading each time you press Single  
and then waits for the next trigger. Continue pressing this key to  
trigger the multimeter.  
Using an External Trigger  
Single  
The external trigger mode is also enabled by pressing  
. It is like  
the single trigger mode except that you apply a trigger pulse to the rear-panel  
Ext Trig terminal. The multimeter is triggered on the negative edge of a  
TTL pulse.  
Single  
The front-panel  
key is disabled when in remote.  
42  
Chapter 2 Front-Panel Menu Operation  
To Use Reading Hold  
To Use Reading Hold  
The reading hold feature allows you to capture and hold a stable  
reading on the display. When a stable reading is detected, the  
multimeter emits a beep and holds the value on the display.  
2
To adjust the reading hold sensitivity band,  
use the TRIG menu.  
Toggles between auto trigger  
and reading hold.  
Hold annunciator is on when  
reading hold is enabled.  
Reading hold has an adjustable sensitivity band to allow you to  
select which readings are considered stable enough to be displayed.  
The band is expressed as a percent of reading on the selected range.  
The multimeter will capture and display a new value only after three  
consecutive readings are within the band.  
The default band is 0.10% of reading. After enabling reading hold,  
you can choose a different band by pressing Shift  
>
(Menu Recall). This takes you to the READ HOLD” command in  
the TRIG MENU (only if reading hold is enabled).  
Go down to the parameter” level, and then select a value:  
0.01%, 0.10%, 1.00%, or 10.00% of reading.  
The sensitivity band is stored in volatile memory; the multimeter  
sets the band to 0.10% of reading when power has been off or after a  
remote interface reset.  
43  
Chapter 2 Front-Panel Menu Operation  
To Make dcv:dcv Ratio Measurements  
To Make dcv:dcv Ratio Measurements  
To calculate a ratio, the multimeter measures a dc reference voltage  
applied to the Sense terminals and the voltage applied to the Input  
terminals.  
dc signal voltage  
Ratio =  
dc reference voltage  
To enable ratio measurements, use the MEAS menu.  
Ratio annunciator is on when  
ratio measurements are enabled.  
At the Sense terminals, the reference voltage measurement function  
is always dc voltage and has a maximum measurable input of  
±12 Vdc. Autoranging is automatically selected for reference voltage  
measurements on the Sense terminals.  
The Input LO and Sense LO terminals must have a common reference  
and cannot have a voltage difference greater than ±2 volts.  
The specified measurement range applies only to the signal connected  
to the Input terminals. The signal on the Input terminals can be any  
dc voltage up to 1000 volts.  
44  
Chapter 2 Front-Panel Menu Operation  
To Make dcv:dcv Ratio Measurements  
The following steps show you how to select the ratio function using the  
front-panel menu.  
On/Off  
Shift  
<
1 Tu r n on t h e m en u .  
2
A: MEAS MENU  
<
<
2 Move d ow n a level a n d t h en a cr oss t o t h e RATIO F UNC com m a n d .  
4: RATIO FUNC  
3 Move d ow n t o t h e pa r a m et er ” level.  
For this command, there is only one choice on this level.  
DCV:DCV  
Auto/Man  
ENTER  
4 Select t h e r a t io fu n ct ion a n d tu r n off th e m en u .  
Notice that the Ratio annunciator turns on.  
CHANGE SAVED  
To disable ratio measurements, select a different measurement function  
by pressing any front-panel function key.  
45  
Chapter 2 Front-Panel Menu Operation  
To Use Reading Memory  
To Use Reading Memory  
The multimeter can store up to 512 readings in internal memory.  
The following steps demonstrate how to store readings and retrieve them.  
1 Select t h e fu n ct ion .  
Select any measurement function. You can also select Null, Min–Max,  
dB, dBm, or limit test. You can change the function at any time during  
reading memory.  
Single  
2 Select t h e sin gle t r igger m od e.  
Notice that the Trig annunciator turns on. When reading memory is  
enabled, readings are stored when you trigger the multimeter.  
For this example, single triggering is used to store readings. You can also  
use auto triggering or reading hold.  
On/Off  
Shift  
<
3 Tu r n on t h e m en u .  
A: MEAS MENU  
>
>
>
4 Move a cr oss t o t h e SYS MENU ch oice on th is level.  
D: SYS MENU  
5 Move d ow n t o a level t o t h e RDGS STORE com m a n d .  
1: RDGS STORE  
46  
Chapter 2 Front-Panel Menu Operation  
To Use Reading Memory  
>
6
Move d ow n a level a n d t h en a cr oss t o t h e ONch oice.  
ON  
2
Auto/Man  
ENTER  
7 Sa ve t h e ch a n ge a n d exit th e m en u .  
Notice that the Mem (memory) annunciator turns on to indicate that the  
multimeter is ready to store readings. Up to 512 readings can be stored  
in first-in-first-out (FIFO) order. When memory is full, the Mem annunciator  
will turn off.  
Readings are preserved until you re-enable reading memory at another  
time, turn off the power, or perform a remote interface reset.  
Single  
Single  
Single  
8 Tr igger t h e m u lt im et er th r ee tim es.  
This stores three readings in memory.  
Recall  
Shift  
>
9 Use m en u r eca ll to r etr ieve th e st or ed r ea d in gs.  
This takes you to the SAVED RDGS” command in the SYS MENU.  
2: SAVED RDGS  
47  
Chapter 2 Front-Panel Menu Operation  
To Use Reading Memory  
10 Move d ow n a level to view t h e fir st st or ed r ea d in g.  
Reading memory is automatically turned off when you go to the  
parameter” level in the menu.  
The first reading displayed is the first reading that was stored (FIFO).  
If no readings are stored in memory, EMPTY” is displayed. The stored  
readings are displayed with their units ( µ, m, k, etc.) when appropriate.  
For example:  
Reading number  
10.31607K: 1  
Exponent  
>
>
11 Move a cr oss t o view t h e tw o r em a in in g st or ed r ea d in gs.  
The readings are stored horizontally on the parameter” level.  
If you press < when you get to the parameter” level, you will see the  
last reading and you will know how many readings were stored.  
On/Off  
Shift  
<
12 Tu r n off t h e m en u .  
EXITING MENU  
48  
3
3
Features and  
Functions  
Features and Functions  
You will find that this chapter makes it easy to look up all the details  
about a particular feature of the multimeter. Whether you are operating  
the multimeter from the front panel or from the remote interface, this  
chapter will be useful. This chapter is divided into the following sections:  
Measurement Configuration, starting on page 51  
Math Operations, starting on page 63  
Triggering, starting on page 71  
System-Related Operations, starting on page 84  
Remote Interface Configuration, starting on page 91  
Calibration Overview, starting on page 95  
Operator Maintenance, starting on page 100  
Power-On and Reset State, on page 101  
Some knowledge of the front-panel menu will be helpful before you read  
this chapter. If you have not already read chapter 2, Front-Panel Menu  
Operation,” starting on page 25, you may want to read it now. Chapter 4,  
Remote Interface Reference,” starting on page 103, lists the syntax for  
the SCPI commands available to program the multimeter.  
Throughout this manual, the following conventions are used for  
SCPI command syntax for remote interface programming.  
Square brackets ( [ ] ) indicate optional keywords or parameters.  
Braces ( { } ) enclose parameters within a command string.  
Triangle brackets ( < > ) indicate that you must substitute a value  
for the enclosed parameter.  
|
A vertical bar ( ) separates multiple parameter choices.  
50  
Chapter 3 Features and Functions  
Measurement Configuration  
Measurement Configuration  
This section contains information to help you configure the multimeter  
for making measurements. You may never have to change any of the  
measurement parameters discussed here, but they are provided to give  
you the flexibility you might need.  
AC Sign a l F ilter  
The multimeter uses three different ac filters which enable you to either  
optimize low frequency accuracy or achieve faster ac settling times.  
The multimeter selects the slow, medium, or fast filter based on the  
input frequency that you specify.  
3
Applies to ac voltage and ac current measurements only.  
Input Frequency  
AC Filter Selected  
Settling Time  
3 Hz to 300 kHz  
20 Hz to 300 kHz  
200 Hz to 300 kHz  
Slow filter  
Medium filter (default)  
Fast filter  
7 seconds / reading  
1 reading / second  
10 readings / second  
The ac filter selection is stored in volatile memory; the multimeter  
selects the medium filter (20 Hz) when power has been off or after a  
remote interface reset.  
Front-Panel Operation: Select from the menu the slow filter (3 Hz),  
medium filter (20 H z), or fast filter (200 Hz). The default is the  
medium filter.  
1: AC FILTER (MEAS MENU)  
Remote Interface Operation: Specify the lowest frequency expected in  
the input signal. The multimeter selects the appropriate filter based  
on the frequency you specify (see table above). The CONFigureand  
MEASure?commands select the 20 Hz filter.  
DETector:BANDwidth {3|20|200|MINimum|MAXimum}  
51  
Chapter 3 Features and Functions  
Measurement Configuration  
Con tin u it y Th r esh old Resist a n ce  
When measuring continuity, the multimeter emits a continuous tone if  
the measured resistance is less than the threshold resistance. You can  
set the threshold to any value between 1 and 1000 .  
The threshold resistance is adjustable only from the front panel.  
The threshold resistance is stored in non-volatile memory, and does not  
change when power has been off or after a remote interface reset.  
The factory setting for the threshold resistance is 10 .  
After enabling the continuity function, you can select a different  
threshold resistance by pressing Shift  
>
(Menu Recall).  
2: CONTINUITY (MEAS MENU)  
0010  
OHM  
See also To Test Continuity,” on page 19.  
52  
Chapter 3 Features and Functions  
Measurement Configuration  
DC In p u t R esist a n ce  
Normally, the multimeters input resistance is fixed at 10 Mfor all  
dc voltage ranges to minimize noise pickup. To reduce the effects of  
measurement loading errors, you can set the input resistance to greater  
than 10 Gfor the 100 mVdc, 1 Vdc, and 10 Vdc ranges.  
Applies to dc voltage measurements and is disabled for all other functions.  
Input Resistance  
Input Resistance  
100mV, 1V, 10V ranges  
100V, 1000V ranges  
3
Fixed Resistance ON (default)  
10 MΩ  
> 10 GΩ  
10 MΩ  
10 MΩ  
Fixed Resistance OFF  
The input resistance setting is stored in volatile memory; the  
multimeter selects 10 M(for all dc voltage ranges) when power  
has been off or after a remote interface reset.  
Front-Panel Operation: Select from the menu the 10 Mmode (fixed  
resistance for all dc voltage ranges) or the >10 Gmode. The default  
is 10 M.  
3: INPUT R (MEAS MENU)  
Remote Interface Operation: You can enable or disable the automatic  
input resistance mode. With AUTO OFF (default), the input resistance  
is fixed at 10 Mfor all ranges. With AUTO ON, the input resistance  
is set to >10 Gfor the three lowest dc voltage ranges. The CONFigure  
and MEASure?commands automatically turn AUTO OFF.  
INPut:IMPedance:AUTO {OFF|ON}  
53  
Chapter 3 Features and Functions  
Measurement Configuration  
Resolu tion  
Resolution is expressed in terms of number of digits the multimeter can  
measure or display. You can set the resolution to 4, 5, or 6 full digits,  
plus a 12” digit which can only be a 0 or 1. To increase measurement  
accuracy and improve noise rejection, select 612 digits. To increase  
measurement speed, select 412 digits.  
Applies to all measurement functions. The resolution for the math  
operations (null, min-max, dB, dBm, limit test) is the same as the  
resolution for the measurement function in use.  
The correspondence between the number of digits selected and the  
resulting integration time (in power line cycles) is shown below.  
The autozero mode is set indirectly when you set the resolution.  
See also Autozero,” on page 59.  
Resolution Choices  
Integration Time  
Fast 4 Digit  
* Slow 4 Digit  
0.02 PLC  
1 PLC  
0.2 PLC  
10 PLC  
Fast 5 Digit  
* Slow 5 Digit (default)  
10 PLC  
100 PLC  
* Fast 6 Digit  
Slow 6 Digit  
* These settings configure the multimeter just as if you had pressed  
the corresponding “DIGITS” keys from the front panel.  
Resolution is local to the selected function. This means that you can  
select the resolution for each function independently. The multimeter  
remembers the resolution when you switch between functions.  
54  
Chapter 3 Features and Functions  
Measurement Configuration  
5 digits  
10.216,5 VDC  
12” digit  
This is the 10 Vdc range, 512 digits are displayed.  
12” digit  
-045.23 mVDC  
3
This is the 100 mVdc range, 412 digits are displayed.  
113.325,6 OHM  
This is the 100 ohm range, 612 digits are displayed.  
The resolution is stored in volatile memory; the multimeter sets the  
resolution to 512 digits (for all functions) when power has been off or  
after a remote interface reset.  
The resolution is fixed at 512 digits for continuity and diode tests.  
For dc and resistance measurements, changing the number of digits  
does more than just change the resolution of the multimeter. It also  
changes the integration time, which is the period the multimeters  
analog-to-digital (A/D) converter samples the input signal for a  
measurement. See also Integration Time,” on page 57.  
For ac measurements, the resolution is actually fixed at 612 digits.  
If you select 412 digits or 512 digits, the multimeter masks” one or  
two digits. The only way to control the reading rate for ac measurements  
is by setting a trigger delay (see page 79).  
For ratio measurements, the specified resolution applies to the signal  
connected to the Input terminals.  
55  
Chapter 3 Features and Functions  
Measurement Configuration  
Resolution  
(continued)  
Front-Panel Operation: Select either the slow or fast mode for each  
resolution setting. The default mode is 5 digits slow.  
5: RESOLUTION (MEAS MENU)  
See also To Set the Resolution,” on page 21.  
Remote Interface Operation: You can set the resolution using the  
following commands.  
CONFigure:<function> {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
MEASure:<function>? {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
<function>:RESolution {<resolution>|MIN|MAX}  
Specify the resolution in the same units as the measurement  
function, not in number of digits. For example, for dc volts, specify the  
resolution in volts. For frequency, specify the resolution in hertz.  
CONF:VOLT:DC 10,0.001  
MEAS:CURR:AC? 1,1E-6  
CONF:FREQ 1 KHZ,0.1 Hz  
VOLT:AC:RES 0.05  
412 digits on the 10 Vdc range  
612 digits on the 1 A range  
1000 Hz input, 0.1 Hz resolution  
50 mV resolution on the ac function  
56  
Chapter 3 Features and Functions  
Measurement Configuration  
In tegr a t ion Tim e  
Integration time is the period during which the multimeters analog-to-  
digital (A/D) converter samples the input signal for a measurement.  
Integration time affects the measurement resolution (for better resolution,  
use a longer integration time), and measurement speed (for faster  
measurements, use a shorter integration time).  
Applies to all measurement functions except ac voltage, ac current,  
frequency, and period. The integration time for the math operations  
(null, min-max, dB, dBm, limit test) is the same as the integration time  
for the measurement function in use.  
3
Integration time is specified in number of power line cycles (NPLCs).  
The choices are 0.02, 0.2, 1, 10, or 100 power line cycles. The default  
is 10 PLCs.  
The integration time is stored in volatile memory; the multimeter  
selects 10 PLCs when power has been off or after a remote  
interface reset.  
Only the integral number of power line cycles (1, 10, or 100 PLCs)  
provide normal mode (line frequency noise) rejection.  
The only way to control the reading rate for ac measurements is by  
setting a trigger delay (see page 79).  
The following table shows the relationship between integration time  
and measurement resolution.  
Integration Time  
Resolution  
0.02 NPLC  
0.2 NPLC  
1 NPLC  
10 NPLC  
100 NPLC  
0.0001 x Full-Scale  
0.00001 x Full-Scale  
0.000003 x Full-Scale  
0.000001 x Full-Scale  
0.0000003 x Full-Scale  
57  
Chapter 3 Features and Functions  
Measurement Configuration  
Integration Time  
(continued)  
Front-Panel Operation: Integration time is set indirectly when you  
select the number of digits. See the table for resolution on page 54.  
Remote Interface Operation:  
<function>:NPLCycles {0.02|0.2|1|10|100|MINimum|MAXimum}  
For frequency and period measurements, aperture time (or gate time)  
is analogous to integration time. Specify 10 ms (412 digits), 100 m s  
(default; 512 digits), or 1 second (612 digits).  
FREQuency:APERture {0.01|0.1|1|MINimum|MAXimum}  
PERiod:APERture {0.01|0.1|1|MINimum|MAXimum}  
F r on t / R ea r In p u t Ter m in a l Swit ch in g  
Any measurement made using the front terminals can also be made  
using the input terminals on the rear panel. See The Front Panel at  
a Glance,” on page 2, for the location of the front /rear switch.  
The input terminals can only be configured from the front panel.  
You cannot select the terminals from the remote interface, but you  
can query the present setting.  
The Rear annunciator turns on when you select the rear terminals.  
Remote Interface Operation: You can query the multimeter to  
determine whether the front or rear input terminals are selected.  
ROUTe:TERMinals?  
returns FRON” or REAR”  
58  
Chapter 3 Features and Functions  
Measurement Configuration  
Au t ozer o  
When autozero is enabled (default), the multimeter internally  
disconnects the input signal following each measurement, and takes a  
zero reading. It then subtracts the zero reading from the preceding  
reading. This prevents offset voltages present on the multimeters input  
circuitry from affecting measurement accuracy.  
When autozero is disabled, the multimeter takes one zero reading and  
subtracts it from all subsequent measurements. It takes a new zero  
reading each time you change the function, range, or integration time.  
3
Applies to dc voltage, dc current, and 2-wire ohms measurements only.  
Autozero is enabled when you select 4-wire ohms or ratio measurements.  
The autozero mode is stored in volatile memory; the multimeter  
automatically enables autozero when power has been off or after a  
remote interface reset.  
Front-Panel Operation: The autozero mode is set indirectly when you  
set the resolution.  
Resolution Choices  
Integration Time  
Autozero  
Fast 4 Digit  
* Slow 4 Digit  
0.02 PLC  
1 PLC  
Off  
On  
0.2 PLC  
10 PLC  
Off  
On  
Fast 5 Digit  
* Slow 5 Digit (default)  
10 PLC  
100 PLC  
On  
On  
* Fast 6 Digit  
Slow 6 Digit  
* These settings configure the multimeter just as if you had  
pressed the corresponding “DIGITS” keys from the front panel.  
Remote Interface Operation: The OFF and ONCE parameters have a  
similar effect. Autozero OFF does not issue a new zero measurement.  
Autozero ONCE issues an immediate zero measurement.  
ZERO:AUTO {OFF|ONCE|ON}  
59  
Chapter 3 Features and Functions  
Measurement Configuration  
Autozero  
(continued)  
The following table shows the relationship between integration time and  
autozero settings from the remote interface and the corresponding  
front-panel settings.  
1
From 34401A Specifications:  
Remote  
Configuration Front-Panel Equivalent  
Digits Displayed Readings/Sec  
NPLC: 100  
Slow 6 digits  
N/A  
N/A  
612  
N/A  
612  
N/A  
512  
N/A  
512  
N/A  
412  
Autozero: On  
Digits Displayed: 612  
NPLC: 100  
Autozero: Off  
Digits Displayed: 612  
NPLC: 10  
Autozero: On  
Digits Displayed: 612  
NPLC: 10  
Autozero: Off  
Digits Displayed: 612  
NPLC: 1  
Autozero: On  
Digits Displayed: 512  
NPLC: 1  
Autozero: Off  
Digits Displayed: 512  
NPLC: 0.2  
Autozero: On  
Digits Displayed: 512  
NPLC: 0.2  
Autozero: Off  
Digits Displayed: 512  
NPLC: 0.02  
N/A  
0.6  
Fast 6 digits  
Slow 5 digits  
N/A  
6
N/A  
Slow 4 digits  
N/A  
N/A  
60  
N/A  
N/A  
300  
N/A  
1000  
Fast 5 digits  
N/A  
Autozero: On  
Digits Displayed: 412  
NPLC: 0.02  
Fast 4 digits  
Autozero: Off  
Digits Displayed: 412  
1
See the Agilent 34401A specifications listed on page 217.  
60  
Chapter 3 Features and Functions  
Measurement Configuration  
Ra n gin g  
You can let the multimeter automatically select the range using  
autoranging or you can select a fixed range using manual ranging.  
Autoranging is convenient because the multimeter automatically selects  
the appropriate range for each measurement. However, you can use  
manual ranging for faster measurements since the multimeter does not  
have to determine which range to use for each measurement.  
The selected mode (auto or manual range) is stored in volatile  
memory; the multimeter returns to autoranging when power has  
been off or after a remote interface reset.  
3
Autorange thresholds:  
Down range at <10% of range  
Up range at >120% of range  
If the input signal is greater than the present range can measure, the  
multimeter gives an overload indication: OVLD” from the front panel  
or “9.90000000E+37” from the remote interface.  
For frequency and period measurements, the multimeter uses one  
range” for all inputs between 3 Hz and 300 kHz. The multimeter  
determines an internal resolution based on a 3 Hz signal. If you  
query the range, the multimeter will respond with 3 Hz. With no  
input signal applied, frequency and period measurements return 0.  
The range is fixed for continuity tests (1 krange) and diode tests  
(1 Vdc range with 1 mA current source output).  
For ratio measurements, the specified range applies to the signal  
connected to the Input terminals. Autoranging is automatically  
selected for reference voltage measurements on the Sense terminals.  
Ranging is local to the selected function. This means that you can select  
the ranging method (auto or manual) for each function independently.  
When manually ranging, the selected range is local to the function; the  
multimeter remembers the range when you switch between functions.  
61  
Chapter 3 Features and Functions  
Measurement Configuration  
Ranging  
(continued)  
Front-Panel Operation: Use the front-panel RANGE keys to select  
autoranging or manual ranging. For frequency and period  
measurements from the front panel, ranging applies to the signals  
input voltage, not its frequency.  
See also To Select a Range,” on page 20.  
Remote Interface Operation: You can set the range using any of the  
following commands.  
CONFigure:<function> {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
MEASure:<function>? {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
<function>:RANGe {<range>|MINimum|MAXimum}  
<function>:RANGe:AUTO {OFF|ON}  
62  
Chapter 3 Features and Functions  
Math Operations  
Math Operations  
There are five math operations available, only one of which can be  
enabled at a time. Each math operation performs a mathematical  
operation on each reading or stores data on a series of readings.  
The selected math operation remains in effect until you disable it,  
change functions, turn off the power, or perform a remote interface  
reset. The math operations use one or more internal registers. You can  
preset the values in some of the registers, while others hold the results  
of the math operation.  
3
The following table shows the math/measurement function combinations  
allowed. Each X” indicates an allowable combination. If you choose a  
math operation that is not allowed with the present measurement  
function, math is turned off. If you select a valid math operation and  
then change to one that is invalid, a Settings conflict” error is generated  
from the remote interface.  
DC V AC V DC I  
AC I  
Freq  
Per  
Cont  
Diode Ratio  
2W  
4W  
X
X
X
X
X
X
X
Null  
Min-Max  
dB  
dBm  
Limit  
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
From the front panel, you enable a math operation by pressing the  
appropriate key. The exception is Limit Test which you enable using the  
LIMIT TEST command in the MATH MENU.  
From the remote interface, the math operations and registers are  
controlled using commands within the CALCulatecommand  
subsystem. First, select the math operation you want to use (the default  
function is null):  
CALCulate:FUNCtion {NULL|DB|DBM|AVERage|LIMit}  
Then, enable the selected math function by turning the math state on:  
CALCulate:STATe ON  
63  
Chapter 3 Features and Functions  
Math Operations  
Min –Ma x Op er a tion  
The min-max operation stores the minimum and maximum readings  
during a series of measurements. The multimeter then calculates the  
average of all readings and records the number of readings taken since  
min-max was enabled.  
Applies to all measurement functions, except continuity and diode.  
After you enable min-max, the first reading that the multimeter  
takes is stored as both the minimum and maximum value.  
The minimum is replaced with any subsequent value that is less.  
The maximum is replaced with any subsequent value that is greater.  
The multimeter displays MIN” or MAXand beeps (if the front-panel  
beeper is enabled) whenever a new minimum or maximum is found.  
It is possible that the multimeter will beep even if the displayed  
reading does not change; this is because the multimeters internal  
resolution may be greater than the displayed resolution. See also  
Beeper Control,” on page 88.  
The minimum, maximum, average, and count are stored in volatile  
memory; the multimeter clears the values when min-max is turned on,  
when power has been off, or after a remote interface reset.  
Front-Panel Operation: After enabling min-max, you can read the  
stored minimum, maximum, average, and count by pressing  
Shift  
>
(Menu Recall). Turning on the menu does not disable  
the min-max operation; the multimeter will resume taking  
measurements when you turn off the menu.  
1: MIN-MAX (MATH MENU)  
See also To Store Minimum and Maximum Readings,” on page 39.  
64  
Chapter 3 Features and Functions  
Math Operations  
Remote Interface Operation: You can use the following commands to  
make min-max measurements.  
CALCulate:FUNCtion AVERage  
CALCulate:STATe {OFF|ON}  
CALCulate:AVERage:MINimum?  
CALCulate:AVERage:MAXimum?  
CALCulate:AVERage:AVERage?  
CALCulate:AVERage:COUNt?  
read the minimum value  
read the maximum value  
read the average of all readings  
read the count  
3
A new command is available starting with firmware Revision 2 which  
allows you to take readings using INITiatewithout storing them in  
internal memory. This command may be useful with the min-max  
operation since it allows you to determine the average of a series of  
readings without storing the individual values.  
DATA:FEED RDG_STORE, ""  
DATA:FEED RDG_STORE, "CALCulate"  
do not store readings  
store readings (default)  
See page 126 for more information on using the DATA:FEEDcommand.  
Nu ll (Rela tive) Op er a t ion  
When making null measurements, also called relative, each reading  
is the difference between a stored null value and the input signal.  
One possible application is in making more accurate two-wire ohms  
measurements by nulling the test lead resistance.  
Resu lt = reading null value  
Applies to all measurement functions, except continuity, diode, and ratio.  
The null value is adjustable and you can set it to any value between  
0 and ±120% of the highest range, for the present function.  
The null value is stored in volatile memory; the value is cleared  
when power has been off, after a remote interface reset, or after a  
function change.  
65  
Chapter 3 Features and Functions  
Math Operations  
Null (Relative)  
(continued)  
The null value is stored in the multimeters Null Register. There are  
two ways you can specify the null value. First, you can enter a  
specific number into the register from the front-panel menu or from  
the remote interface. Any previously stored value is replaced with the  
new value. If you are operating the multimeter from the front panel,  
entering a null value also turns on the null function.  
The second way to enter the null value is to let the multimeter store  
the first reading in the register. After you enable null, the first  
reading displayed will be zero (if you have not changed the value  
stored in the register). If you entered a number into the register, as  
described in the paragraph above, the first reading does not overwrite  
the stored value.  
Front-Panel Operation: After enabling null, you can edit the stored  
null value by pressing Shift  
>
(Menu Recall). Any previously  
stored value is replaced with the new value. Turning on the menu  
does not disable the null operation; the multimeter will resume  
taking measurements when you turn off the menu.  
2: NULL VALUE (MATH MENU)  
See also To Make Null (Relative) Measurements,” on page 38.  
Remote Interface Operation: You can use the following commands to  
make null measurements. Math must be enabled before you can store  
a value in the Null Register.  
CALCulate:FUNCtion NULL  
CALCulate:STATe {OFF|ON}  
CALCulate:NULL:OFFSet {<value>|MINimum|MAXimum}  
The following program segment shows the proper order that you  
should execute the commands to enable null and set an offset value.  
CALC:FUNC NULL  
CALC:STAT ON  
CALC:NULL:OFFS -2.0  
66  
Chapter 3 Features and Functions  
Math Operations  
d B Mea su r em en ts  
Each dB measurement is the difference between the input signal and a  
stored relative value, with both values converted to dBm.  
d B = reading in dBm relative value in dBm  
Applies to dc voltage and ac voltage measurements only.  
The relative value is adjustable and you can set it to any value  
between 0 dBm and ±200.00 dBm.  
3
The relative value is stored in volatile memory; the value is cleared  
when power has been off, after a remote interface reset, or after a  
function change.  
The relative value is stored in the multimeters dB Relative Register.  
There are two ways you can specify the relative value. First, you can  
enter a specific number into the register from the front-panel menu or  
from the remote interface. Any previously stored value is replaced  
with the new value. If you are operating the multimeter from the front  
panel, entering a relative value also turns on the dB function.  
The second way to enter the relative value is to let the multimeter  
take the first reading, convert it to dBm, and store that value in the  
register. Changing the dBm reference resistance (see page 68) does  
not change the stored relative value. After you enable dB, the first  
reading taken will be 0 dB (if you have not changed the value stored in  
the register). If you entered a number into the register, as described in the  
paragraph above, the first reading does not overwrite the stored value.  
Front-Panel Operation: After enabling dB, you can edit the stored  
relative value by pressing Shift  
>
(Menu Recall). Any previously  
stored value is replaced with the new value. Turning on the menu  
does not disable the dB operation; the multimeter will resume  
taking measurements when you turn off the menu.  
3: dB REL (MATH MENU)  
See also To Make dB Measurements,” on page 40.  
67  
Chapter 3 Features and Functions  
Math Operations  
Remote Interface Operation: You can use the following commands to  
make dB measurements. Math must be enabled before you can store a  
value to the Relative Register.  
CALCulate:FUNCtion DB  
CALCulate:STATe {OFF|ON}  
CALCulate:DB:REFerence {<value>|MINimum|MAXimum}  
d Bm Mea su r em en ts  
The dBm operation calculates the power delivered to a resistance  
referenced to 1 milliwatt.  
d Bm = 10 × Log10 ( reading2 / reference resistance / 1 mW )  
Applies to dc voltage and ac voltage measurements only.  
You can choose from 17 different reference resistance values.  
The factory setting for the reference resistance is 600.  
The choices are: 50, 75, 93, 110, 124, 125, 135, 150, 250, 300, 500,  
600, 800, 900, 1000, 1200, or 8000 ohms.  
The reference resistance is stored in non-volatile memory, and does not  
change when power has been off or after a remote interface reset.  
Front-Panel Operation: After enabling dBm, you can select a new  
reference resistance by pressing Shift  
>
(Menu Recall). Turning  
on the menu does not disable the dBm operation; the multimeter  
will resume taking measurements when you turn off the menu.  
4: dBm REF R (MATH MENU)  
See also To Make dBm Measurements,” on page 41.  
Remote Interface Operation: You can use the following commands to  
make dBm measurements.  
CALCulate:FUNCtion DBM  
CALCulate:STATe {OFF|ON}  
CALCulate:DBM:REFerence {<value>|MINimum|MAXimum}  
68  
Chapter 3 Features and Functions  
Math Operations  
Lim it Test in g  
The limit test operation enables you to perform pass/fail testing to  
upper and lower limits that you specify.  
Applies to all measurement functions, except continuity and diode tests.  
You can set the upper and lower limits to any value between 0 and  
±120% of the highest range, for the present function. The upper limit  
selected should always be a more positive number than the lower  
limit. The default upper and lower limits are both 0.  
The upper and lower limits are stored in volatile memory; the  
multimeter sets both limits to 0 when power has been off, after a  
remote interface reset, or after a function change.  
3
You can configure the multimeter to generate a service request (SRQ)  
on the first occurrence of a failed reading. See The SCPI Status  
Model,” starting on page 134 for more information.  
Front-Panel Operation: The multimeter displays OK” for each  
reading that is within the specified limits. It displays HI” or LO” for  
each reading that exceeds the upper or lower limit. The multimeter  
beeps once (if the front-panel beeper is enabled) on the first  
occurrence of a failed reading after a good reading. See also Beeper  
Control,” on page 88.  
5: LIMIT TEST (MATH MENU)  
6: HIGH LIMIT (MATH MENU)  
enable or disable limit test  
set the upper limit  
7: LOW LIMIT  
(MATH MENU)  
set the lower limit  
You can also turn off limit test by selecting a different math operation  
from the front panel (only one math operation can be enabled at a time).  
69  
Chapter 3 Features and Functions  
Math Operations  
Limit Testing  
Remote Interface Operation: You can use the following commands for  
limit testing.  
(continued)  
CALCulate:FUNCtion LIMit  
CALCulate:STATe {OFF|ON}  
CALCulate:LIMit:LOWer {<value>|MINimum|MAXimum}  
CALCulate:LIMit:UPPer {<value>|MINimum|MAXimum}  
There are two unused pins on the RS-232 interface connector which  
are available to indicate the pass/fail status of readings taken with  
limit testing. To configure these pins for limit testing, you must  
install two jumpers inside the multimeter. See the Service Guide for  
more information.  
A low-going pulse is output to pin 1 for each reading that is within  
the specified limits. A low-going pulse is output to pin 9 for each  
reading that exceeds the upper or lower limit.  
1
5 V  
0 V  
9
Pin 1: Pass Output  
Pin 9: Fail Output  
2 ms  
minimum  
C a u t i o n  
Do not use the RS-232 interface if you have configured the multimeter to  
output pass/ fail signals on pins 1 and 9. Internal components on the  
RS-232 interface circuitry may be damaged.  
70  
Chapter 3 Features and Functions  
Triggering  
Triggering  
The multimeters triggering system allows you to generate triggers  
either manually or automatically, take multiple readings per trigger,  
and insert a delay before each reading. Normally, the multimeter will  
take one reading each time it receives a trigger, but you can specify  
multiple readings (up to 50,000) per trigger.  
You can trigger the multimeter from the front panel using a single  
trigger, an external trigger, or auto triggering. Single triggering  
takes one reading each time you press the Single key. External  
triggering is like single triggering, but the multimeter waits for a  
pulse on the rear-panel Ext Trig (external trigger) terminal before  
taking a reading. Auto triggering takes continuous readings at the  
fastest rate possible for the present configuration. See also To Trigger  
the Multimeter,” on page 42.  
3
Triggering the multimeter from the remote interface is a multi-step  
process that offers triggering flexibility.  
First, you must configure the multimeter for the measurement by  
selecting the function, range, resolution, etc.  
Then, you must specify the source from which the multimeter will  
accept the trigger. The multimeter will accept a software (bus) trigger  
from the remote interface, a hardware trigger from the Ext Trig  
terminal, or an immediate internal trigger.  
Then, you must make sure that the multimeter is ready to accept a  
trigger from the specified trigger source (this is called the  
wait-for-trigger state).  
The diagram on the next page shows the multimeters triggering system.  
71  
Chapter 3 Features and Functions  
Triggering  
Agilen t 34401A Tr igger in g System  
Idle  
State  
Initiate Triggering  
MEASure?  
READ?  
INITiate  
Wait-for-  
Trigger  
State  
Trigger Source  
TRIGger:SOURce IMMediate  
TRIGger:SOURce EXTernal  
TRIGger:SOURce BUS  
Front-panel “Single” key  
Trigger Delay  
TRIGger:DELay  
Delay  
Sample ( )  
Annunciator  
Measurement  
Sample  
Sample  
Trigger  
Count 1 Count 1  
72  
Chapter 3 Features and Functions  
Triggering  
Tr igger Sou r ce Ch oices  
You must specify the source from which the multimeter will accept a  
trigger. From the front panel, the multimeter will accept a single  
trigger, a hardware trigger from the Ext Trig terminal, or continuously  
take readings using auto trigger. At power-on, auto triggering is used.  
From the remote interface, the multimeter will accept a software (bus)  
trigger, a hardware trigger from the Ext Trig terminal, or an immediate  
internal trigger. The Q (sample) annunciator turns on during each  
measurement.  
The trigger source is stored in volatile memory; the source is set to  
auto trigger (front panel) or immediate (remote interface) when  
power has been off or after a remote interface reset.  
3
To select the trigger source from the remote interface, use the  
following command. The CONFigureand MEASure?commands  
automatically set the trigger source to IMMediate.  
TRIGger:SOURce {BUS|IMMediate|EXTernal}  
Au to Tr igger in g In the auto trigger mode (front panel only), the  
multimeter continuously takes readings at the fastest rate possible  
for the present configuration. This is the power-on trigger source for  
front-panel operation.  
Sin gle Tr igger in g In the single trigger mode (front panel only),  
you can manually trigger the multimeter by pressing Single .  
The multimeter takes one reading, or the specified number of  
readings (sample count), each time you press the key. The Trig  
annunciator turns on when the multimeter is waiting for a trigger.  
The front-panel Single key is disabled when in remote.  
73  
Chapter 3 Features and Functions  
Triggering  
Exter n a l Tr igger in g In the external trigger mode, the multimeter  
will accept a hardware trigger applied to the Ext Trig terminal.  
The multimeter takes one reading, or the specified number of readings  
(sample count), each time Ext Trig receives a low-true pulse.  
See also External Trigger Terminal,” on page 83.  
The multimeter buffers one external trigger. This means that if the  
multimeter is taking a reading and another external trigger occurs,  
that trigger is accepted (a Trigger ignored” error is not reported).  
After the reading in progress is complete, the stored trigger satisfies  
the trigger source and then the trigger is issued.  
Front-Panel Operation: The external trigger mode is like the single  
trigger mode except that you apply the trigger to the Ext Trig  
terminal. Pressing Single to enable the single trigger mode also  
enables the external trigger mode. The Trig annunciator turns on  
when the multimeter is waiting for an external trigger.  
The front-panel Single key is disabled when in remote.  
Remote Interface Operation:  
TRIGger:SOURce EXTernal  
74  
Chapter 3 Features and Functions  
Triggering  
Inter n a l Tr igger in g In the internal trigger mode (remote interface only),  
the trigger signal is always present. When you place the multimeter in  
the wait-for-trigger state, the trigger is issued immediately. This is the  
power-on trigger source for remote interface operation.  
To select the internal trigger source, send the following command.  
The CONFigureand MEASure?commands automatically set the  
trigger source to IMMediate.  
TRIGger:SOURce IMMediate  
3
Softwa r e (Bu s) Tr igger in g The bus trigger mode is available only  
from the remote interface. This mode is similar to the single trigger  
mode from the front panel, but you trigger the multimeter by sending  
a bus trigger command.  
To select the bus trigger source, send the following command.  
TRIGger:SOURce BUS  
To trigger the multimeter from the remote interface (GPIB or RS-232),  
send the *TRG(trigger) command. The *TRGcommand will not be  
accepted unless the multimeter is in the wait-for-trigger state.  
You can also trigger the multimeter from the GPIB interface by  
sending the IEEE-488 Group Execute Trigger (GET) message.  
The multimeter must be in the wait-for-trigger state. The following  
statement shows how to send a GET using BASIC.  
TRIGGER 722  
Group Execute Trigger  
75  
Chapter 3 Features and Functions  
Triggering  
Th e Wa it -for -Tr igger Sta t e  
After you have configured the multimeter and selected a trigger source,  
you must place the multimeter in the wait-for-trigger state. A trigger  
will not be accepted until the multimeter is in this state. If a trigger  
signal is present, and if multimeter is in the wait-for-trigger” state,  
the measurement sequence begins and readings are taken.  
The wait-for-trigger” state is a term used primarily for remote interface  
operation. From the front panel, the multimeter is always in the  
wait-for- trigger” state and will accept triggers at any time, unless a  
measurement is already in progress.  
You can place the multimeter in the wait-for-trigger” state by executing  
any of the following commands from the remote interface.  
MEASure?  
READ?  
INITiate  
The multimeter requires approximately 20 ms of set-up time after you  
send a command to change to the wait-for-trigger” state. Any external  
triggers that occur during this set-up time are ignored.  
Ha ltin g a Mea su r em en t in P r ogr ess  
You can send a device clear at any time to halt a measurement in  
progress and place the multimeter in the idle state.” The following  
statement shows how to send a device clear over the GPIB interface  
using BASIC.  
CLEAR 722  
IEEE-488 Device Clear  
A device clear does not affect the configuration of the triggering system.  
The trigger source, sample count, trigger delay, and number of triggers  
are not changed.  
76  
Chapter 3 Features and Functions  
Triggering  
Nu m b er of Sa m p les  
Normally, the multimeter takes one reading (or sample) each time it  
receives a trigger from the selected trigger source (if the multimeter is  
in the wait-for-trigger state). You can, however, instruct the multimeter  
to take multiple readings for each trigger received.  
Number of samples: 1 to 50,000. The default is 1 sample per trigger.  
The selected number of samples is stored in volatile memory; the  
multimeter sets the sample count to 1 when power has been off or  
after a remote interface reset. The CONFigureand MEASure?  
commands automatically set the sample count to 1.  
3
Front-Panel Operation:  
3: N SAMPLES (TRIG MENU)  
Remote Interface Operation:  
SAMPle:COUNt {<value>|MINimum|MAXimum}  
77  
Chapter 3 Features and Functions  
Triggering  
Nu m b er of Tr igger s  
Normally, the multimeter will accept only one trigger before returning  
to the idle” trigger state. You can, however, instruct the multimeter to  
accept multiple triggers.  
This feature is available only from the remote interface. If you set the  
trigger count and then go to local (front panel), the multimeter ignores  
the trigger count setting; when you return to remote, the trigger count  
returns to the value you selected.  
Number of triggers: 1 to 50,000. The default is 1 trigger.  
The selected number of triggers is stored in volatile memory; the  
multimeter sets the trigger count to 1 when power has been off or  
after a remote interface reset. The CONFigureand MEASure?  
commands automatically set the trigger count to 1.  
Remote Interface Operation:  
TRIGger:COUNt {<value>|MINimum|MAXimum|INFinite}  
78  
Chapter 3 Features and Functions  
Triggering  
Tr igger Dela y  
You can insert a delay between the trigger signal and each sample that  
follows. This may be useful in applications where you want to allow the  
input to settle before taking a reading, or for pacing a burst of readings.  
If you do not specify a trigger delay, the multimeter automatically  
selects a delay for you.  
Delay range: 0 to 3600 seconds. The default trigger delay is  
automatic; the delay is determined by function, range, integration time,  
and ac filter setting (see also Automatic Trigger Delays,” on page 81).  
The trigger delay is stored in volatile memory; the multimeter selects  
an automatic trigger delay when power has been off or after a remote  
interface reset. The CONFigureand MEASure?commands  
automatically set the trigger delay to automatic.  
3
If you specify a delay other than automatic, that same delay is used  
for all functions and ranges.  
If you have configured the multimeter to take more than one reading  
per trigger (sample count > 1), the specified trigger delay is inserted  
between the trigger and each reading.  
Front-Panel Operation: You can use an automatic trigger delay or  
you can specify a delay in seconds.  
2: TRIG DELAY (TRIG MENU)  
If an automatic trigger delay is enabled, AUTO” is displayed  
momentarily before the actual number of seconds is displayed.  
--- AUTO ---  
79  
Chapter 3 Features and Functions  
Triggering  
Trigger Delay  
(continued)  
Front-Panel Operation (continued)  
To set the delay to 0 seconds, select the parameter” level of the TRIG  
DELAY command. Move the flashing cursor to the units” location on  
the right side of the display. Press  
then press Menu Enter.  
until ZERO DELAY is reached,  
ZERO DELAY  
To select the automatic trigger delay, select the parameter” level  
of the TRIG DELAY command. Move the flashing cursor to the  
units” location on the right side of the display. Press  
AUTO DELAY is reached, then press Menu Enter.  
until  
AUTO DELAY  
Remote Interface Operation:  
You can use the following command to set the trigger delay.  
TRIGger:DELay {<seconds>|MINimum|MAXimum}  
You can use the following command to set an automatic trigger delay.  
TRIGger:DELay:AUTO {OFF|ON}  
80  
Chapter 3 Features and Functions  
Triggering  
Au t om a tic Tr igger Dela ys  
If you do not specify a trigger delay, the multimeter selects an  
automatic delay for you. The delay is determined by function, range,  
integration time, and ac filter setting.  
DC Voltage and DC Current (for all ranges):  
Integration Time  
Trigger Delay  
NPLC 1  
NPLC < 1  
1.5 ms  
1.0 ms  
3
Resistance (2-wire and 4-wire):  
Trigger Delay  
Trigger Delay  
Range  
Range  
(For NPLC 1)  
(For NPLC < 1)  
100 Ω  
1 kΩ  
10 kΩ  
100 kΩ  
1 MΩ  
100 Ω  
1 kΩ  
10 kΩ  
100 kΩ  
1 MΩ  
1.0 ms  
1.0 ms  
1.0 ms  
1.0 ms  
10 ms  
1.5 ms  
1.5 ms  
1.5 ms  
1.5 ms  
15 ms  
10 MΩ  
100 MΩ  
10 MΩ  
100 MΩ  
100 ms  
100 ms  
100 ms  
100 ms  
AC Voltage and AC Current (for all ranges):  
Front panel with auto trigger ON  
Remote or single/external trigger  
AC Filter  
Trigger Delay  
AC Filter  
Trigger Delay  
Slow  
Medium  
Fast  
7.0 sec  
1.0 sec  
600 ms  
Slow  
Medium  
Fast  
1.5 sec  
200 ms  
100 ms  
Frequency and Period:  
Remote or single/external trigger  
Front panel with auto trigger ON  
Trigger Delay  
Trigger Delay  
1.0 sec  
0 sec  
81  
Chapter 3 Features and Functions  
Triggering  
Rea d in g Hold  
The reading hold feature allows you to capture and hold a stable  
reading on the front-panel display. This is especially useful in situations  
where you want to take a reading, remove the test probes, and have the  
reading remain on the display. When a stable reading is detected, the  
multimeter emits a beep (if the front-panel beeper is enabled) and holds  
the reading on the display. See also Beeper Control,” on page 88.  
The reading hold feature is available only from the front panel. If you go  
to remote when reading hold is enabled, the multimeter ignores it; when  
you return to local (front panel), reading hold is enabled again.  
Reading hold has an adjustable sensitivity band (adjustable only from  
the front panel) to allow you to select which readings are considered  
stable enough to be displayed. The band is expressed as a percent of  
reading, on the selected range. The multimeter will capture and display  
a new value only after three consecutive readings are within the band.  
Select one of these values: 0.01%, 0.10% (default), 1.00%, or 10.00%  
of reading. For example, assume that the 1.00% band is selected and  
a 5 volt signal is applied to the multimeter. If three consecutive  
readings are between 4.975 volts and 5.025 volts, the display will show  
a new reading.  
The sensitivity band is stored in volatile memory; the multimeter sets  
the band to 0.10% when power has been off or after an interface reset.  
If the multimeter is in autorange when you enable reading hold,  
it will autorange to the correct range. If the multimeter is in the  
manual range mode, the same fixed range will be used for reading hold.  
When reading hold is enabled, the input resistance is automatically  
set to 10 M(AUTO OFF) for all dc voltage ranges. This helps to  
minimize noise pickup when the test leads are open-circuit.  
For certain applications, it may be useful to use reading hold with  
reading memory. See also Reading Memory,” on page 84.  
Front-Panel Operation: After enabling reading hold, you can select a  
different sensitivity band by pressing Shift > (Menu Recall).  
1: READ HOLD (TRIG MENU)  
See also To Use Reading Hold,” on page 43.  
82  
Chapter 3 Features and Functions  
Triggering  
Voltm eter Com p let e Ter m in a l  
The rear-panel VM Comp (voltmeter complete) terminal provides a  
low-true pulse after the completion of each measurement. Voltmeter  
complete and external trigger (see below) implement a standard hardware  
handshake sequence between measurement and switching devices.  
Output  
5 V  
0 V  
3
Approximately  
2 µs  
Exter n a l Tr igger Ter m in a l  
You can trigger the multimeter by applying a low-true pulse to the  
rear-panel Ext Trig (external trigger) terminal. To use this terminal  
from the remote interface, you must select the external trigger source  
(TRIGger:SOURce EXTernal).  
Input  
5 V  
0 V  
>1 µs  
You can use a simple switch to generate an external trigger using the  
Ext Trig input as shown below.  
Ext Trig  
83  
Chapter 3 Features and Functions  
System-Related Operations  
System-Related Operations  
This section gives information on topics such as reading memory, errors,  
self-test, and front-panel display control. This information is not directly  
related to making measurements but is an important part of operating  
the multimeter.  
Rea d in g Mem or y  
The multimeter can store up to 512 readings in internal memory.  
Readings are stored in first-in-first-out (FIFO) order. The first reading  
returned is the first reading stored. The reading memory feature is  
available only from the front panel.  
You can use reading memory with all functions, math operations, and  
also reading hold. After you have enabled reading memory, you can  
change the function. Be aware, however, that the function labels  
(VDC, OHM, etc.) are not stored with the reading.  
Readings taken while reading memory is enabled are stored in  
volatile memory; the multimeter clears the stored readings when  
reading memory is turned on again, when power has been off, after a  
self-test, or after a remote interface reset.  
You can use reading memory with auto trigger, single trigger,  
external trigger, and reading hold. If you configure the multimeter for  
multiple readings per trigger, the specified number of readings are  
stored in memory each time a trigger is received.  
Front-Panel Operation:  
1: RDGS STORE (SYS MENU)  
2: SAVED RDGS (SYS MENU)  
store readings in memory  
read the stored readings  
Reading memory is automatically turned off when you go to the  
parameter” level in the menu to recall the readings. See also To Use  
Reading Memory,” on page 46.  
Remote Interface Operation: The INITiatecommand uses reading  
memory to store readings prior to a FETCh?command. You can query  
the number of stored readings in memory by sending the  
DATA:POINts?command from the remote interface.  
84  
Chapter 3 Features and Functions  
System-Related Operations  
E r r or Con d it ion s  
When the front-panel ERROR annunciator turns on, one or more  
command syntax or hardware errors have been detected. A record of up  
to 20 errors is stored in the multimeters error queue. See chapter 5,  
Error Messages,” for a complete listing of the errors.  
Errors are retrieved in first-in-first-out (FIFO) order. The first  
error returned is the first error that was stored. When you have  
read all errors from the queue, the ERROR annunciator turns off.  
The multimeter beeps once each time an error is generated.  
If more than 20 errors have occurred, the last error stored in the  
queue (the most recent error) is replaced with -350, Too many errors.  
No additional errors are stored until you remove errors from the  
queue. If no errors have occurred when you read the error queue,  
the multimeter responds with +0, No error.  
3
The error queue is cleared when power has been off or after a *CLS  
(clear status) command has been executed. The *RST(reset)  
command does not clear the error queue.  
Front-Panel Operation:  
3: ERROR (SYS MENU)  
If the ERROR annunciator is on, press Shift  
<
(Recall Menu) to  
read the errors stored in the queue. The errors are listed  
horizontally on the parameter” level. All errors are cleared when  
you go to the parameter” level and then turn off the menu.  
ERR 1: -113  
Error code  
First error in queue  
Remote Interface Operation:  
SYSTem:ERRor?  
Reads one error from the error queue  
Errors have the following format (the error string may contain  
up to 80 characters):  
-113,"Undefined header"  
85  
Chapter 3 Features and Functions  
System-Related Operations  
Self-Test  
A power-on self-test occurs automatically when you turn on the  
multimeter. This limited test assures you that the multimeter is  
operational. This self-test does not perform the extensive set of analog  
tests that are included as part of the complete self-test described below.  
A complete self-test runs a series of tests and takes approximately  
15 seconds to execute. If all tests pass, you can have a high confidence  
that the multimeter is operational.  
The results of the complete self-test are stored in internal reading  
memory (see page 84). Memory is cleared as the self-test stores this  
information. Other than clearing memory, the complete self-test  
does not alter the state of the multimeter.  
If the complete self-test is successful, PASS” is displayed on the front  
panel. If the self-test fails, FAIL” is displayed and the ERROR  
annunciator turns on. See the Service Guide for instructions on  
returning the multimeter to Agilent for service.  
Front-Panel Operation: You can perform some of the tests (complete  
self-test) individually or you can perform all tests together at once.  
4: TEST (SYS MENU)  
Another way to perform the complete front-panel self-test is as follows:  
Hold down Shift as you press the Power switch to turn on the  
multimeter; hold down the key for more than 5 seconds. The self-  
test will begin when you release the key.  
Remote Interface Operation:  
*TST?  
Returns 0” if the self-test is successful, or 1” if it fails.  
86  
Chapter 3 Features and Functions  
System-Related Operations  
Disp la y Con tr ol  
To speed up your measurement rate, or for security reasons, you may  
want to turn off the front-panel display. From the remote interface, you  
can also display a 12-character message on the front panel.  
When the display is turned off, readings are not sent to the display  
and all display annunciators except ERROR and Shift are disabled.  
Front-panel operation is otherwise unaffected by turning off the display.  
The display state is stored in volatile memory; the display is enabled  
when power has been off or after a remote interface reset.  
3
You can display a message on the front panel by sending a  
command from the remote interface. The multimeter can display up  
to 12 characters of the message on the front panel; any additional  
characters are truncated. Commas, periods, and semicolons share a  
display space with the preceding character, and are not considered  
individual characters. When a message is displayed, readings are not  
sent to the display.  
Sending a message to the display from the remote interface overrides  
the display state; this means that you can display a message even if  
the display is turned off.  
Front-Panel Operation:  
5: DISPLAY (SYS MENU)  
The display always turns on for menu operation; this means that  
even when the display is turned off, you can still operate the menu.  
Remote Interface Operation:  
DISPlay {OFF|ON}  
DISPlay:TEXT <quoted string> display the string enclosed in quotes  
DISPlay:TEXT:CLEar clear the displayed message  
disable/ enable the display  
The following command string shows how to display a message on the  
front panel.  
"DISP:TEXT ’HELLO’"  
87  
Chapter 3 Features and Functions  
System-Related Operations  
Beep er Con t r ol  
Normally, the multimeter will emit a tone whenever certain conditions  
are met from the front panel. For example, the multimeter will beep  
when a stable reading is captured in reading hold. You may want to  
disable the front-panel beeper for certain applications.  
When you disable the beeper, the multimeter will not emit a tone when:  
1) a new minimum or maximum is found in a min–max test.  
2) a stable reading is captured in reading hold.  
3) a limit is exceeded in a limit test.  
4) a forward-biased diode is measured in the diode test function.  
Disabling the beeper has no effect on the tone generated when:  
1) an error is generated.  
2) the continuity threshold is exceeded.  
3) you turn off the front-panel menu.  
Turning off the beeper does not disable the key click generated when  
you press a front-panel key.  
The beeper state is stored in non-volatile memory, and does not  
change when power has been off or after a remote interface reset.  
The beeper is enabled when the multimeter is shipped from the factory.  
Front-Panel Operation:  
6: BEEP (SYS MENU)  
Remote Interface Operation:  
SYSTem:BEEPer  
SYSTem:BEEPer:STATe {OFF|ON}  
issue a single beep immediately  
disable/ enable beeper state  
88  
Chapter 3 Features and Functions  
System-Related Operations  
Com m a Sep a r a tor s  
The multimeter can display readings on the front panel with or without  
a comma separator. This feature is available only from the front panel.  
08.241,53 VDC  
08.24153 VDC  
With comma separator (factory setting)  
Without comma separator  
The display format is stored in non-volatile memory, and does not  
3
change when power has been off or after a remote interface reset.  
The comma separator is enabled when the multimeter is shipped  
from the factory.  
Front-Panel Operation:  
7: COMMA (SYS MENU)  
See also To Turn Off the Comma Separator,” on page 37.  
F ir m wa r e Revision Qu er y  
The multimeter has three microprocessors for control of various internal  
systems. You can query the multimeter to determine which revision of  
firmware is installed for each microprocessor.  
The multimeter returns three numbers. The first number is the  
firmware revision number for the measurement processor; the second  
is for the input/output processor; and the third is for the front-panel  
processor.  
Front-Panel Operation:  
8: REVISION (SYS MENU)  
REV XX-XX-XX  
Remote Interface Operation:  
*IDN?  
returns “HEWLETT-PACKARD,34401A,0,XX-XX-XX”  
Be sure to dimension a string variable with at least 35 characters.  
89  
Chapter 3 Features and Functions  
System-Related Operations  
SCP I La n gu a ge Ver sion Qu er y  
The multimeter complies with the rules and regulations of the present  
version of SCPI (Standard Commands for Programmable Instruments).  
You can determine the SCPI version with which the multimeter is in  
compliance by sending a command from the remote interface.  
You cannot query the SCPI version from the front panel.  
The following command returns the SCPI version.  
SYSTem:VERSion?  
Returns a string in the form YYYY.V” where the Y’s” represent the  
year of the version, and the V represents a version number for that  
year (for example, 1991.0).  
90  
Chapter 3 Features and Functions  
Remote Interface Configuration  
Remote Interface Configuration  
This section gives information on configuring the remote interface.  
For additional information, see chapter 4, Remote Interface Reference,”  
starting on page 103.  
GP IB Ad d r ess  
Each device on the GPIB (IEEE-488) interface must have a unique  
address. You can set the multimeters address to any value between  
0 and 31. The address is set to 22” when the multimeter is shipped  
from the factory. The GPIB address is displayed at power-on.  
3
The GPIB address can be set only from the front-panel.  
The address is stored in non-volatile memory, and does not change  
when power has been off or after a remote interface reset.  
You can set the address to 31” which is the talk only mode. In this  
mode, the multimeter can output readings directly to a printer  
without being addressed by a bus controller (over either GPIB or  
RS-232). For proper operation, make sure your printer is configured in  
the listen always mode. Address 31 is not a valid address if you are  
operating the multimeter from the GPIB interface with a bus controller.  
If you select the RS-232 interface and then set the GPIB address to the  
talk only address (31), the multimeter will send readings over the  
RS-232 interface when in the local mode.  
If you select the RS-232 interface and then set the GPIB address to the  
talk only address (31), the multimeter will send readings over the  
RS-232 interface when in the local mode.  
Your GPIB bus controller has its own address. Be sure to avoid using  
the bus controllers address for any instrument on the interface bus.  
Agilent controllers generally use address 21.  
Front-Panel Operation:  
1: GPIB ADDR (I/O MENU)  
See also To Set the GPIB Address,” on page 161.  
91  
Chapter 3 Features and Functions  
Remote Interface Configuration  
Rem ote In ter fa ce Select ion  
The multimeter is shipped with both an GPIB (IEEE-488) interface  
and an RS-232 interface. Only one interface can be enabled at a time.  
The GPIB interface is selected when the multimeter is shipped from  
the factory.  
The remote interface can be set only from the front-panel.  
The interface selection is stored in non-volatile memory, and does not  
change when power has been off or after a remote interface reset.  
If you select the GPIB interface, you must select a unique address for  
the multimeter. The GPIB address is displayed when you turn on the  
multimeter.  
If you select the RS-232 interface, you must set the baud rate and  
parity for the multimeter. RS-232” is displayed when you turn on the  
multimeter.  
If you select the RS-232 interface and then set the GPIB address to the  
talk only address (31), the multimeter will send readings over the  
RS-232 interface when in the local mode.  
There are certain restrictions to be aware of when you are selecting  
the remote interface (see also Programming Language Selection,” on  
page 94). The only programming language supported on RS-232 is SCPI.  
GPIB / 488  
RS-232  
X
Not allowed  
Not allowed  
SCPI Language  
3478A Language  
Fluke 8840A Language  
X
X
X
Front-Panel Operation:  
2: INTERFACE (I/O MENU)  
See also To Select the Remote Interface,” on page 162.  
92  
Chapter 3 Features and Functions  
Remote Interface Configuration  
Ba u d R a te Selection (RS-232)  
You can select one of six baud rates for RS-232 operation. The rate is set  
to 9600 baud when the multimeter is shipped from the factory.  
The baud rate can be set only from the front-panel.  
Select one of the following: 300, 600, 1200, 2400, 4800, or 9600 baud  
(factory setting).  
The baud rate selection is stored in non-volatile memory, and does not  
change when power has been off or after a remote interface reset.  
3
Front-Panel Operation:  
3: BAUD RATE (I/O MENU)  
See also To Set the Baud Rate,” on page 163.  
P a r it y Select ion (RS-232)  
You can select the parity for RS-232 operation. The multimeter is  
configured for even parity with 7 data bits when shipped from the factory.  
The parity can be set only from the front-panel.  
Select one of the following: None (8 data bits), E ven (7 data bits), or  
Odd (7 data bits). When you set the parity, you are indirectly setting  
the number of data bits.  
The parity selection is stored in non-volatile memory, and does not  
change when power has been off or after a remote interface reset.  
Front-Panel Operation:  
4: PARITY (I/O MENU)  
See also To Set the Parity,” on page 164.  
93  
Chapter 3 Features and Functions  
Remote Interface Configuration  
P r ogr a m m in g La n gu a ge Selection  
You can select one of three languages to program the multimeter from  
the selected remote interface. The language is SCPI when the multimeter is  
shipped from the factory.  
Select one of the following: SCP I, Agilent 3478A, or Fluke 8840A.  
The language selection is stored in non-volatile memory, and does not  
change when power has been off or after a remote interface reset.  
There are certain restrictions to be aware of when you are selecting  
the interface language (see also Remote Interface Selection,” on  
page 92). The Agilent 3478A and Fluke 8840A/8842A languages  
are not supported on the RS-232 interface.  
GPIB / 488  
RS-232  
X
SCPI Language  
X
3478A Language  
Fluke 8840A Language  
X
Not allowed  
Not allowed  
X
Front-Panel Operation:  
5: LANGUAGE (I/O MENU)  
See also To Select the Programming Language,” on page 165.  
Remote Interface Operation:  
L1  
L2  
L3  
select SCPI language  
select Agilent 3478A language  
select Fluke 8840A language  
94  
Chapter 3 Features and Functions  
Calibration Overview  
Calibration Overview  
This section gives a brief introduction to the calibration features of the  
multimeter. For a more detailed discussion of the calibration procedures,  
see chapter 4 in the Service Guide.  
Ca lib r a tion Secu r it y  
This feature allows you to enter a security code to prevent accidental or  
unauthorized calibrations of the multimeter. When you first receive  
your multimeter, it is secured. Before you can calibrate the multimeter,  
you must unsecure it by entering the correct security code.  
3
The security code is set to HP034401” when the multimeter is shipped  
from the factory. The security code is stored in non-volatile memory,  
and does not change when power has been off or after a remote  
interface reset.  
To secure the multimeter from the remote interface, the security code  
may contain up to 12 alphanumeric characters as shown below.  
The first character must be a letter, but the remaining characters can  
be letters or numbers. You do not have to use all 12 characters but  
the first character must always be a letter.  
A _ _ _ _ _ _ _ _ _ _ _  
(12 characters)  
To secure the multimeter from the remote interface so that it can be  
unsecured from the front panel, use the eight-character format shown  
below. The first two characters must be HP” and the remaining  
characters must be numbers. Only the last six characters are  
recognized from the front panel, but all eight characters are required.  
(To unsecure the multimeter from the front panel, omit the HP” and  
enter the remaining numbers as shown on the following pages.)  
H P _ _ _ _ _ _  
(8 characters)  
If you forget your security code, you can disable the security feature by  
adding a jumper inside the multimeter, and then entering a new code.  
See the Service Guide for more information.  
95  
Chapter 3 Features and Functions  
Calibration Overview  
Calibration  
Security  
(continued)  
To Un secu r e for Ca libr a tion You can unsecure the multimeter  
for calibration either from the front panel or remote interface.  
The multimeter is secured when shipped from the factory, and the  
security code is set to HP034401.  
Front-Panel Operation:  
1: SECURED (CAL MENU)  
If the multimeter is secured, you will see the above command when  
you go into the CAL MENU. (If you move across the commands” level  
in the menu, you will notice that the 2: CALIBRATE” command is  
hidden” if the multimeter is secured.) To unsecure the multimeter,  
select the parameter” level of the SECURED command, enter the  
security code, then press Menu Enter.  
000000 CODE  
When you go to the commands” level in the CAL MENU again,  
you will notice that the multimeter is unsecured. Notice also that the  
2: CALIBRATE” command is no longer hidden and you can perform  
a calibration.  
1: UNSECURED  
Remote Interface Operation:  
CALibration:SECure:STATe {OFF|ON},<code>  
To unsecure the multimeter, send the above command with the same  
code used to secure. For example,  
"CAL:SEC:STAT OFF,HP034401"  
96  
Chapter 3 Features and Functions  
Calibration Overview  
To Secu r e Aga in st Ca libr a tion You can secure the multimeter  
against calibration either from the front panel or remote interface.  
The multimeter is secured when shipped from the factory, and the  
security code is set to HP034401.  
Make sure you have read the security code rules on page 95 before  
attempting to secure the multimeter.  
Front-Panel Operation:  
1: UNSECURED (CAL MENU)  
3
If the multimeter is unsecured, you will see the above command when  
you go into the CAL MENU. To secure the multimeter, select the  
parameter” level of the UNSECURED command, enter the security  
code, then press Menu Enter.  
000000 CODE  
When you go to the commands” level in the CAL MENU again,  
you will notice that the multimeter is secured. Notice also that the  
2: CALIBRATE” command is now hidden and you cannot perform  
a calibration.  
1: SECURED  
Remote Interface Operation:  
CALibration:SECure:STATe {OFF|ON},<code>  
To secure the multimeter, send the above command with the same  
code as used to unsecure. For example,  
"CAL:SEC:STAT ON,HP034401"  
97  
Chapter 3 Features and Functions  
Calibration Overview  
Calibration  
Security  
(continued)  
To Ch a n ge th e Secu r ity Cod e To change the security code, you must  
first unsecure the multimeter, and then enter a new code. Make sure  
you have read the security code rules on page 95 before attempting to  
secure the multimeter.  
Front-Panel Operation: To change the security code, first make sure  
that the multimeter is unsecured. Select the parameter” level of the  
UNSECURED command, enter the new security code, then press  
Menu Enter. Changing the code from the front panel also changes the  
code as seen from the remote interface.  
Remote Interface Operation:  
CALibration:SECure:CODE <new code>  
To change the security code, first unsecure the multimeter using the  
old security code. Then, enter the new code. For example,  
CAL:SEC:STAT OFF, HP034401  
CAL:SEC:CODE ZZ010443  
unsecure with old code  
enter new code  
Ca lib r a tion Cou n t  
You can determine the number of times that your multimeter has been  
calibrated. Your multimeter was calibrated before it left the factory.  
When you receive your multimeter, read the count to determine its  
initial value.  
The calibration count is stored in non-volatile memory, and does not  
change when power has been off or after a remote interface reset.  
The calibration count increments up to a maximum of 32,767 after  
which it wraps-around to 0. Since the value increments by one for  
each calibration point, a complete calibration increases the value by  
several counts.  
Front-Panel Operation:  
3: CAL COUNT (CAL MENU)  
Remote Interface Operation:  
CALibration:COUNt?  
98  
Chapter 3 Features and Functions  
Calibration Overview  
Ca lib r a tion Messa ge  
You can use the calibration message feature to record calibration  
information about your multimeter. For example, you can store such  
information as the last calibration date, the next calibration due date,  
the multimeters serial number, or even the name and phone number of  
the person to contact for a new calibration.  
You can record information in the calibration message only from the  
remote interface. However, you can read the message from either the  
front-panel menu or the remote interface.  
3
The calibration message may contain up to 40 characters. However,  
the multimeter can display only 12 characters of the message on the  
front panel (additional characters are truncated).  
The calibration message is stored in non-volatile memory, and  
does not change when power has been off or after a remote  
interface reset.  
Front-Panel Operation:  
4: MESSAGE (CAL MENU)  
read the cal message  
Remote Interface Operation:  
CALibration:STRing <quoted string>  
store the cal message  
The following command string shows how to store a calibration message.  
"CAL:STR ’CAL 2-1-96’"  
99  
Chapter 3 Features and Functions  
Operator Maintenance  
Operator Maintenance  
This section describes how to replace the power-line and current fuses.  
If you need additional information about replacing parts or repairing  
the multimeter, see the Service Guide.  
To Rep la ce th e P ower -Lin e F u se  
The power-line fuse is located within the multimeters fuse-holder  
assembly on the rear panel (see also page 15). See the rear panel of the  
multimeter for the proper fuse rating. To replace the 250 mAT fuse,  
order Agilent part number 2110-0817.  
To Rep la ce th e Cu r r en t In p u t F u ses  
The front and rear current input terminals are protected by two series  
fuses. The first fuse is a 3A, 250 Vac, fast-blow fuse and is located on the  
rear panel. To replace this fuse, order Agilent part number 2110-0780.  
With a small flatblade screwdriver, push in on the fuse cap  
and rotate it counterclockwise. Remove the fuse cap and fuse.  
A second fuse is located inside the multimeter to provide an additional  
level of current protection. This fuse is a 7A, 250 Vac, high-interrupt  
rated fuse (Agilent part number 2110-0614). To replace this fuse, you  
must remove the multimeters case by loosening three screws. See the  
Service Guide for more information on disassembling the multimeter.  
100  
Chapter 3 Features and Functions  
Power-On and Reset State  
Power-On and Reset State  
The parameters marked with a bullet ( ) are stored in non-volatile memory.  
The factory settings are shown.  
Measurement  
AC Filter  
Autozero  
Configuration  
Power-On/Reset State  
20 Hz (medium filter)  
On  
Continuity Threshold  
10 Ω  
Function  
DC volts  
Input Resistance  
Integration Time  
Range  
10 M(fixed for all dcv ranges)  
10 PLCs  
Autorange  
512 digits, slow mode  
3
Resolution  
For your convenience,  
this table is duplicated  
on the rear cover of this  
manual and on the  
Math Operations  
Math State, Function  
Math Registers  
Power-On/Reset State  
Off, Null  
All registers are cleared  
dBm Reference Resistance  
600 Ω  
Quick Reference Card.  
Triggering Operations  
Reading Hold Threshold  
Samples Per Trigger  
Trigger Delay  
Power-On/Reset State  
0.10% of range  
1 sample  
Automatic Delay  
Auto Trigger  
Trigger Source  
System-Related  
Operations  
Power-On/Reset State  
Beeper Mode  
Comma Separators  
Display Mode  
On  
On  
On  
Reading Memory  
Off (cleared)  
Input/Output  
Configuration  
Power-On/Reset State  
Baud Rate  
GPIB Address  
Interface  
Language  
Parity  
9600 baud  
22  
GPIB (IEEE-488)  
SCPI  
Even (7 data bits)  
Calibration  
Calibration State  
Power-On/Reset State  
Secured  
101  
102  
4
4
Remote Interface  
Reference  
Remote Interface Reference  
Command Summary, starting on page 105  
>
Simplified Programming Overview, starting on page 112  
The MEASure? and CONFigure Commands, starting on page 117  
Measurement Configuration Commands, starting on page 121  
Math Operation Commands, starting on page 124  
Triggering, starting on page 127  
Triggering Commands, starting on page 130  
System-Related Commands, starting on page 132  
The SCPI Status Model, starting on page 134  
Status Reporting Commands, starting on page 144  
Calibration Commands, on page 146  
RS-232 Interface Configuration, starting on page 148  
RS-232 Interface Commands, on page 153  
>
An Introduction to the SCPI Language, starting on page 154  
Output Data Formats, on page 159  
Using Device Clear to Halt Measurements, on page 160  
TALK ONLY for Printers, on page 160  
To Set the GPIB Address, on page 161  
To Select the Remote Interface, on page 162  
To Set the Baud Rate, on page 163  
To Set the Parity, on page 164  
To Select the Programming Language, on page 165  
Alternate Programming Language Compatibility, starting on page 166  
SCPI Compliance Information, on page 168  
IEEE-488 Compliance Information, on page 169  
If you are a first-time user of the SCPI language, you may want to refer to these sections  
to become familiar with the language before attempting to program the multimeter.  
104  
Chapter 4 Remote Interface Reference  
Command Summary  
Command Summary  
This section summarizes the SCPI (Standard Commands for  
Programmable Instruments) commands available to program the  
multimeter. Refer to the later sections in this chapter for more complete  
details on each command.  
Throughout this manual, the following conventions are used for  
SCPI command syntax. Squa re bra ckets ( [ ] ) indicate optional  
keywords or parameters. Braces ( { } ) enclose parameters within a  
command string. Triangle brackets ( < > ) indicate that you must  
substitute a value for the enclosed parameter.  
The MEASure? and CONFigure Commands  
(see page 117 for more information)  
4
First-time  
SCPI users,  
see page 154.  
MEASure  
:VOLTage:DC? {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
:VOLTage:DC:RATio? {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
:VOLTage:AC? {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
:CURRent:DC? {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
:CURRent:AC? {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
:RESistance? {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
:FRESistance? {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
:FREQuency? {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
:PERiod? {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
:CONTinuity?  
:DIODe?  
CONFigure  
:VOLTage:DC {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
:VOLTage:DC:RATio {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
:VOLTage:AC {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
:CURRent:DC {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
:CURRent:AC {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
:RESistance {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
:FRESistance {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
:FREQuency {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
:PERiod {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
:CONTinuity  
:DIODe  
CONFigure?  
105  
Chapter 4 Remote Interface Reference  
Command Summary  
Measurement Configuration Commands  
(see page 121 for more information)  
[SENSe:]  
FUNCtion "VOLTage:DC"  
FUNCtion "VOLTage:DC:RATio"  
FUNCtion "VOLTage:AC"  
FUNCtion "CURRent:DC"  
FUNCtion "CURRent:AC"  
FUNCtion "RESistance"  
(2-wire ohms)  
(4-wire ohms)  
FUNCtion "FRESistance"  
FUNCtion "FREQuency"  
FUNCtion "PERiod"  
FUNCtion "CONTinuity"  
FUNCtion "DIODe"  
FUNCtion?  
[SENSe:]  
VOLTage:DC:RANGe {<range>|MINimum|MAXimum}  
VOLTage:DC:RANGe? [MINimum|MAXimum]  
VOLTage:AC:RANGe {<range>|MINimum|MAXimum}  
VOLTage:AC:RANGe? [MINimum|MAXimum]  
CURRent:DC:RANGe {<range>|MINimum|MAXimum}  
CURRent:DC:RANGe? [MINimum|MAXimum]  
CURRent:AC:RANGe {<range>|MINimum|MAXimum}  
CURRent:AC:RANGe? [MINimum|MAXimum]  
RESistance:RANGe {<range>|MINimum|MAXimum}  
RESistance:RANGe? [MINimum|MAXimum]  
FRESistance:RANGe {<range>|MINimum|MAXimum}  
FRESistance:RANGe? [MINimum|MAXimum]  
FREQuency:VOLTage:RANGe {<range>|MINimum|MAXimum}  
FREQuency:VOLTage:RANGe? [MINimum|MAXimum]  
PERiod:VOLTage:RANGe {<range>|MINimum|MAXimum}  
PERiod:VOLTage:RANGe? [MINimum|MAXimum]  
[SENSe:]  
VOLTage:DC:RANGe:AUTO {OFF|ON}  
VOLTage:DC:RANGe:AUTO?  
VOLTage:AC:RANGe:AUTO {OFF|ON}  
VOLTage:AC:RANGe:AUTO?  
CURRent:DC:RANGe:AUTO {OFF|ON}  
CURRent:DC:RANGe:AUTO?  
CURRent:AC:RANGe:AUTO {OFF|ON}  
CURRent:AC:RANGe:AUTO?  
RESistance:RANGe:AUTO {OFF|ON}  
RESistance:RANGe:AUTO?  
FRESistance:RANGe:AUTO {OFF|ON}  
FRESistance:RANGe:AUTO?  
FREQuency:VOLTage:RANGe:AUTO {OFF|ON}  
FREQuency:VOLTage:RANGe:AUTO?  
PERiod:VOLTage:RANGe:AUTO {OFF|ON}  
PERiod:VOLTage:RANGe:AUTO?  
Default parameters are shown in bold.  
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Command Summary  
Measurement Configuration Commands  
(continued)  
[SENSe:]  
VOLTage:DC:RESolution {<resolution>|MINimum|MAXimum}  
VOLTage:DC:RESolution? [MINimum|MAXimum]  
VOLTage:AC:RESolution {<resolution>|MINimum|MAXimum}  
VOLTage:AC:RESolution? [MINimum|MAXimum]  
CURRent:DC:RESolution {<resolution>|MINimum|MAXimum}  
CURRent:DC:RESolution? [MINimum|MAXimum]  
CURRent:AC:RESolution {<resolution>|MINimum|MAXimum}  
CURRent:AC:RESolution? [MINimum|MAXimum]  
RESistance:RESolution {<resolution>|MINimum|MAXimum}  
RESistance:RESolution? [MINimum|MAXimum]  
FRESistance:RESolution {<resolution>|MINimum|MAXimum}  
FRESistance:RESolution? [MINimum|MAXimum]  
[SENSe:]  
VOLTage:DC:NPLCycles {0.02|0.2|1|10|100|MINimum|MAXimum}  
VOLTage:DC:NPLCycles? [MINimum|MAXimum]  
CURRent:DC:NPLCycles {0.02|0.2|1|10|100|MINimum|MAXimum}  
CURRent:DC:NPLCycles? [MINimum|MAXimum]  
RESistance:NPLCycles {0.02|0.2|1|10|100|MINimum|MAXimum}  
RESistance:NPLCycles? [MINimum|MAXimum]  
4
FRESistance:NPLCycles {0.02|0.2|1|10|100|MINimum|MAXimum}  
FRESistance:NPLCycles? [MINimum|MAXimum]  
[SENSe:]  
FREQuency:APERture {0.01|0.1|1|MINimum|MAXimum}  
FREQuency:APERture? [MINimum|MAXimum]  
PERiod:APERture {0.01|0.1|1|MINimum|MAXimum}  
PERiod:APERture? [MINimum|MAXimum]  
[SENSe:]  
DETector:BANDwidth {3|20|200|MINimum|MAXimum}  
DETector:BANDwidth? [MINimum|MAXimum]  
[SENSe:]  
ZERO:AUTO {OFF|ONCE|ON}  
ZERO:AUTO?  
INPut  
:IMPedance:AUTO {OFF|ON}  
:IMPedance:AUTO?  
ROUTe:TERMinals?  
Default parameters are shown in bold.  
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Command Summary  
Math Operation Commands  
(see page 124 for more information)  
CALCulate  
:FUNCtion {NULL|DB|DBM|AVERage|LIMit}  
:FUNCtion?  
:STATe {OFF|ON}  
:STATe?  
CALCulate  
:AVERage:MINimum?  
:AVERage:MAXimum?  
:AVERage:AVERage?  
:AVERage:COUNt?  
CALCulate  
:NULL:OFFSet {<value>|MINimum|MAXimum}  
:NULL:OFFSet? [MINimum|MAXimum]  
CALCulate  
:DB:REFerence {<value>|MINimum|MAXimum}  
:DB:REFerence? [MINimum|MAXimum]  
CALCulate  
:DBM:REFerence {<value>|MINimum|MAXimum}  
:DBM:REFerence? [MINimum|MAXimum]  
CALCulate  
:LIMit:LOWer {<value>|MINimum|MAXimum}  
:LIMit:LOWer? [MINimum|MAXimum]  
:LIMit:UPPer {<value>|MINimum|MAXimum}  
:LIMit:UPPer? [MINimum|MAXimum]  
DATA:FEED RDG_STORE, {"CALCulate"|""}  
DATA:FEED?  
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Command Summary  
Triggering Commands  
(see page 127 for more information)  
INITiate  
READ?  
TRIGger  
:SOURce {BUS|IMMediate|EXTernal}  
:SOURce?  
TRIGger  
:DELay {<seconds>|MINimum|MAXimum}  
:DELay? [MINimum|MAXimum]  
TRIGger  
:DELay:AUTO {OFF|ON}  
:DELay:AUTO?  
SAMPle  
:COUNt {<value>|MINimum|MAXimum}  
:COUNt? [MINimum|MAXimum]  
4
TRIGger  
:COUNt {<value>|MINimum|MAXimum|INFinite}  
:COUNt? [MINimum|MAXimum]  
System-Related Commands  
(see page 132 for more information)  
SYSTem:ERRor?  
FETCh?  
READ?  
SYSTem:VERSion?  
DATA:POINts?  
*RST  
DISPlay {OFF|ON}  
DISPlay?  
*TST?  
DISPlay  
:TEXT <quoted string>  
:TEXT?  
*IDN?  
:TEXT:CLEar  
L1  
L2  
L3  
SYSTem  
:BEEPer  
:BEEPer:STATe {OFF|ON}  
:BEEPer:STATe?  
Default parameters are shown in bold.  
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Command Summary  
Status Reporting Commands  
(see page 144 for more information)  
SYSTem:ERRor?  
STATus  
:QUEStionable:ENABle <enable value>  
:QUEStionable:ENABle?  
:QUEStionable:EVENt?  
STATus:PRESet  
*CLS  
*ESE <enable value>  
*ESE?  
*ESR?  
*OPC  
*OPC?  
*PSC {0|1}  
*PSC?  
*SRE <enable value>  
*SRE?  
*STB?  
Calibration Commands  
(see page 146 for more information)  
CALibration?  
CALibration:COUNt?  
CALibration  
:SECure:CODE <new code>  
:SECure:STATe {OFF|ON},<code>  
:SECure:STATe?  
CALibration  
:STRing <quoted string>  
:STRing?  
CALibration  
:VALue <value>  
Default parameters are shown in bold.  
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Command Summary  
RS-232 Interface Commands  
(see page 148 for more information)  
SYSTem:LOCal  
SYSTem:REMote  
SYSTem:RWLock  
IEEE-488.2 Common Commands  
(see page 169 for more information)  
*CLS  
*ESE <enable value>  
*ESE?  
*ESR?  
*IDN?  
*OPC  
4
*OPC?  
*PSC {0|1}  
*PSC?  
*RST  
*SRE <enable value>  
*SRE?  
*STB?  
*TRG  
*TST?  
Default parameters are shown in bold.  
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Simplified Programming Overview  
Simplified Programming Overview  
You can program the multimeter to take measurements from the remote  
interface using the following simple seven-step sequence.  
First-time  
SCPI users,  
see page 154.  
1. Place the multimeter in a known state (often the reset state).  
2. Change the multimeters settings to achieve the desired configuration.  
3. Set-up the triggering conditions.  
4. Initiate or arm the multimeter for a measurement.  
5. Trigger the multimeter to make a measurement.  
6. Retrieve the readings from the output buffer or internal memory.  
7. Read the measured data into your bus controller.  
The MEASure?and CONFigurecommands provide the most straight-  
forward method to program the multimeter for measurements. You can  
select the measurement function, range, and resolution all in one  
command. The multimeter automatically presets other measurement  
parameters (ac filter, autozero, trigger count, etc.) to default values as  
shown below.  
MEASure? and CONFigure Preset States  
Command  
MEASure? and CONFigure Setting  
AC Filter (DET:BAND)  
Autozero (ZERO:AUTO)  
20 Hz (medium filter)  
OFF if resolution setting results in NPLC < 1;  
ON if resolution setting results in NPLC 1  
Input Resistance (INP:IMP:AUTO)  
Samples per Trigger (SAMP:COUN)  
Trigger Count (TRIG:COUN)  
OFF (fixed at 10 Mfor all dc voltage ranges)  
1 sample  
1 trigger  
Trigger Delay (TRIG:DEL)  
Trigger Source (TRIG:SOUR)  
Math Function (CALCulate subsystem)  
Automatic delay  
Immediate  
OFF  
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Usin g th e MEASu r e? Com m a n d  
The easiest way to program the multimeter for measurements is by  
using the MEASure?command. However, this command does not offer  
much flexibility. When you execute the command, the multimeter  
presets the best settings for the requested configuration and  
immediately performs the measurement. You cannot change any  
settings (other than function, range, and resolution) before the  
measurement is taken. The results are sent to the output buffer.  
Sending the MEASure? command is the same as sending a CONFigure  
command followed immediately by a READ? command.  
Usin g th e CONF igu r e Com m a n d  
For a little more programming flexibility, use the CONFigurecommand.  
When you execute the command, the multimeter presets the best  
settings for the requested configuration (like the MEASure?command).  
However, the measurement is not automatically started and you can  
change measurement parameters before making measurements. This  
allows you to incrementally” change the multimeters configuration  
from the preset conditions. The multimeter offers a variety of low-level  
commands in the INPut, SENSe, CALCulate, and TRIGger  
4
subsystems. (You can use the SENSe:FUNCtioncommand to change the  
measurement function without using MEASure?or CONFigure.)  
Use the INITiate or READ? command to initiate the measurement.  
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Usin g th e r a n ge a n d r esolu tion P a r a m et er s  
With the MEASure?and CONFigurecommands, you can select the  
measurement function, range, and resolution all in one command.  
Use the range parameter to specify the expected value of the input  
signal. The multimeter then selects the correct measurement range.  
For frequency and period measurements, the multimeter uses one  
range” for all inputs between 3 Hz and 300 kHz. The range parameter  
is required only to specify the resolution. Therefore, it is not necessary  
to send a new command for each new frequency to be measured.  
Use the resolution parameter to specify the desired resolution for  
the measurement. Specify the resolution in the same units as the  
measurement function, not in number of digits. For example, for  
dc volts, specify the resolution in volts. For frequency, specify the  
resolution in hertz.  
You must specify a range to use the resolution parameter.  
Usin g th e READ? Com m a n d  
The READ?command changes the state of the trigger system from the  
idle” state to the wait-for-trigger” state. Measurements will begin  
when the specified trigger conditions are satisfied following the receipt  
of the READ?command. Readings are sent immediately to the output  
buffer. You must enter the reading data into your bus controller or the  
multimeter will stop making measurements when the output buffer  
fills. Readings are not stored in the multimeters internal memory when  
using the READ?command.  
Sending the READ? command is like sending the INITiate command  
followed immediately by the FETCh? command, except readings are not  
buffered internally.  
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C a u t i o n  
If you send two query commands without reading the response from the  
first, and then attempt to read the second response, you may receive some  
data from the first response followed by the complete second response.  
To avoid this, do not send a query command without reading the  
response. When you cannot avoid this situation, send a device clear  
before sending the second query command.  
Usin g th e INITia t e a n d F ETCh ? Com m a n d s  
The INITiateand FETCh?commands provide the lowest level of  
control (with the most flexibility) of measurement triggering and  
reading retrieval. Use the INITiatecommand after you have  
configured the multimeter for the measurement. This changes the state  
of the triggering system from the idle” state to the wait-for-trigger”  
state. Measurements will begin when the specified trigger conditions  
are satisfied after the INITiatecommand is received. The readings are  
placed in the multimeters internal memory (up to 512 readings can be  
stored). Readings are stored in memory until you are able to retrieve them.  
4
Use the FETCh?command to transfer the readings from the  
multimeters internal memory to the multimeters output buffer where  
you can read them into your bus controller.  
MEASure?  
Example  
The following program segment shows how to use the MEASure?  
command to make a measurement. This example configures the  
multimeter for dc voltage measurements, automatically places the  
multimeter in the wait-for-trigger” state, internally triggers the  
multimeter to take one reading, and then sends the reading to the  
output buffer.  
MEAS:VOLT:DC? 10,0.003  
bus enter statement  
This is the simplest way to take a reading. However, you do not have  
any flexibility with MEASure?to set the trigger count, sample count,  
trigger delay, etc. All measurement parameters except function, range,  
and resolution are preset for you automatically (see the table on page 112).  
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CONFigure  
Example  
The following program segment shows how to use the READ?command  
with CONFigureto make an externally-triggered measurement.  
The program configures the multimeter for dc voltage measurements.  
CONFiguredoes not place the multimeter in the wait-for-trigger” state.  
The READ?command places the multimeter in the wait-for-trigger”  
state, takes a reading when the Ext Trig terminal is pulsed, and sends  
the reading to the output buffer.  
CONF:VOLT:DC 10, 0.003  
TRIG:SOUR EXT  
READ?  
bus enter statement  
CONFigure  
Example  
The following program segment is similar to the program above but it  
uses INITiateto place the multimeter in the wait-for-trigger” state.  
The INITiatecommand places the multimeter in the wait-for-trigger”  
state, takes a reading when the Ext Trig terminal is pulsed, and sends  
the reading to the multimeters internal memory. The FETCh?command  
transfers the reading from internal memory to the output buffer.  
CONF:VOLT:DC 10, 0.003  
TRIG:SOUR EXT  
INIT  
FETC?  
bus enter statement  
Storing readings in memory using the INITiatecommand is faster  
than sending readings to the output buffer using the READ?command.  
The multimeter can store up to 512 readings in internal memory. If you  
configure the multimeter to take more than 512 readings (using the  
sample count and trigger count), and then send INITiate, a memory  
error is generated.  
After you execute an INITiatecommand, no further commands are  
accepted until the measurement sequence is completed. However, if you  
select TRIGger:SOURce BUS, the multimeter will accept the *TRG  
command (bus trigger) or an IEEE-488 Group Execute Trigger message.  
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The MEASure? and CONFigure Commands  
The MEASure? and CONFigure Commands  
See also Measurement Configuration,” starting on page 51 in chapter 3.  
For the range parameter, MIN selects the lowest range for the  
selected function; MAX selects the highest range; DEF selects  
autoranging.  
For the resolution parameter, specify the resolution in the same units  
as the measurement function, not in number of digits. MIN selects the  
smallest value accepted, which gives the best resolution; MAX selects  
the largest value accepted, which gives the least resolution;  
DEF selects the default resolution which is 512 digits slow (10 PLC).  
Note: You must specify a r a n ge to use the r esolu tion parameter.  
4
MEASure:VOLTage:DC? {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
Preset and make a dc voltage measurement with the specified range  
and resolution. The reading is sent to the output buffer.  
MEASure:VOLTage:DC:RATio? {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
Preset and make a dc:dc ratio measurement with the specified range  
and resolution. The reading is sent to the output buffer. For ratio  
measurements, the specified range applies to the signal connected to the  
Input terminals. Autoranging is automatically selected for reference  
voltage measurements on the Sense terminals.  
MEASure:VOLTage:AC? {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
Preset and make an ac voltage measurement with the specified range  
and resolution. The reading is sent to the output buffer. For ac  
measurements, resolution is actually fixed at 612 digits. The resolution  
parameter only affects the front-panel display.  
MEASure:CURRent:DC? {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
Preset and make a dc current measurement with the specified range  
and resolution. The reading is sent to the output buffer.  
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MEASure:CURRent:AC? {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
Preset and make an ac current measurement with the specified range  
and resolution. The reading is sent to the output buffer. For ac  
measurements, resolution is actually fixed at 612 digits. The resolution  
parameter only affects the front-panel display.  
MEASure:RESistance? {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
Preset and make a 2-wire ohms measurement with the specified range  
and resolution. The reading is sent to the output buffer.  
MEASure:FRESistance? {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
Preset and make a 4-wire ohms measurement with the specified range  
and resolution. The reading is sent to the output buffer.  
MEASure:FREQuency? {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
Preset and make a frequency measurement with the specified range and  
resolution. The reading is sent to the output buffer. For frequency  
measurements, the multimeter uses one range” for all inputs between  
3 Hz and 300 kHz. With no input signal applied, frequency measurements  
return 0.  
MEASure:PERiod? {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
Preset and make a period measurement with the specified range and  
resolution. The reading is sent to the output buffer. For period  
measurements, the multimeter uses one range” for all inputs between  
0.33 seconds and 3.3 µsec. With no input signal applied, period  
measurements return 0.  
MEASure:CONTinuity?  
Preset and make a continuity measurement. The reading is sent to the  
output buffer. The range and resolution are fixed for continuity tests  
(1 krange and 512 digits).  
MEASure:DIODe?  
Preset and make a diode measurement. The reading is sent to the  
output buffer. The range and resolution are fixed for diode tests  
(1 Vdc range with 1 mA current source output and 512 digits).  
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The MEASure? and CONFigure Commands  
CONFigure:VOLTage:DC {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
Preset and configure the multimeter for dc voltage measurements with  
the specified range and resolution. This command does not initiate the  
measurement.  
CONFigure:VOLTage:DC:RATio {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
Preset and configure the multimeter for dc:dc ratio measurements with  
the specified range and resolution. This command does not initiate the  
measurement. For ratio measurements, the specified range applies to  
the signal connected to the Input terminals. Autoranging is automatically  
selected for reference voltage measurements on the Sense terminals.  
CONFigure:VOLTage:AC {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
Preset and configure the multimeter for ac voltage measurements with  
the specified range and resolution. This command does not initiate the  
measurement. For ac measurements, resolution is actually fixed at  
612 digits. The resolution parameter only affects the front-panel display.  
4
CONFigure:CURRent:DC {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
Preset and configure the multimeter for dc current measurements with  
the specified range and resolution. This command does not initiate the  
measurement.  
CONFigure:CURRent:AC {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
Preset and configure the multimeter for ac current measurements with  
the specified range and resolution. This command does not initiate the  
measurement. For ac measurements, resolution is actually fixed at  
612 digits. The resolution parameter only affects the front-panel display.  
CONFigure:RESistance {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
Preset and configure the multimeter for 2-wire ohms measurements  
with the specified range and resolution. This command does not initiate  
the measurement.  
CONFigure:FRESistance {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
Preset and configure the multimeter for 4-wire ohms measurements  
with the specified range and resolution. This command does not initiate  
the measurement.  
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CONFigure:FREQuency {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
Preset and configure a frequency measurement with the specified range  
and resolution. This command does not initiate the measurement.  
For frequency measurements, the multimeter uses one range” for all  
inputs between 3 Hz and 300 kHz. With no input signal applied,  
frequency measurements return 0.  
CONFigure:PERiod {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}  
Preset and configure a period measurement with the specified range  
and resolution. This command does not initiate the measurement.  
For period measurements, the multimeter uses one range” for all inputs  
between 0.33 seconds and 3.3 µsec. With no input signal applied, period  
measurements return 0.  
CONFigure:CONTinuity  
Preset and configure the multimeter for continuity measurements.  
This command does not initiate the measurement. The range and  
resolution are fixed for continuity tests (1 krange and 512 digits).  
CONFigure:DIODe  
Preset and configure the multimeter for diode measurements.  
This command does not initiate the measurement. The range and  
resolution are fixed for diode tests (1 Vdc range with 1 mA current  
source output and 512 digits).  
CONFigure?  
Query the multimeters present configuration and return a quoted string.  
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Measurement Configuration Commands  
Measurement Configuration Commands  
See also Measurement Configuration,” starting on page 51 in chapter 3.  
FUNCtion "<function>"  
Select a measurement function. The function must be enclosed in quotes  
in the command string (FUNC "VOLT:DC"). Specify one of the following  
strings.  
VOLTage:DC  
VOLTage:DC:RATio  
VOLTage:AC  
FRESistance (4-wire ohms)  
FREQuency  
PERiod  
CURRent:DC  
CONTinuity  
CURRent:AC  
DIODe  
RESistance (2-wire ohms)  
FUNCtion?  
4
Query the measurement function and return a quoted string.  
<function>:RANGe {<range>|MINimum|MAXimum}  
Select the range for the selected function. For frequency and period  
measurements, ranging applies to the signals input voltage, not its  
frequency (use FREQuency:VOLTageor PERiod:VOLTage). MIN selects  
the lowest range for the selected function. MAX selects the highest  
range. [Stored in volatile memory]  
<function>:RANGe? [MINimum|MAXimum]  
Query the range for the selected function.  
<function>:RANGe:AUTO {OFF|ON}  
Disable or enable autoranging for the selected function. For frequency  
and period, use FREQuency:VOLTage or PERiod:VOLTage.  
Autorange thresholds: Down range at <10% of range; Up range  
at >120% of range. [Stored in volatile memory]  
<function>:RANGe:AUTO?  
Query the autorange setting. Returns 0” (OFF) or 1” (ON).  
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<function>:RESolution {<resolution>|MINimum|MAXimum}  
Select the resolution for the specified function (not valid for frequency,  
period, or ratio). Specify the resolution in the same units as the  
measurement function, not in number of digits. MIN selects the smallest  
value accepted, which gives the most resolution. MAX selects the largest  
value accepted which gives the least resolution. [Stored in volatile memory]  
<function>:RESolution? [MINimum|MAXimum]  
Query the resolution for the selected function. For frequency or period  
measurements, the multimeter returns a resolution setting based upon  
a 3 Hz input frequency.  
<function>:NPLCycles {0.02|0.2|1|10|100|MINimum|MAXimum}  
Select the integration time in number of power line cycles for the  
present function (the default is 10 PLC). This command is valid only for  
dc volts, ratio, dc current, 2-wire ohms, and 4-wire ohms. MIN = 0.02.  
MAX = 100. [Stored in volatile memory]  
<function>:NPLCycles? [MINimum|MAXimum]  
Query the integration time for the selected function.  
FREQuency:APERture {0.01|0.1|1|MINimum|MAXimum}  
Select the aperture time (or gate time) for frequency measurements  
(the default is 0.1 seconds). Specify 10 ms (412 digits), 100 m s (default;  
512 digits), or 1 second (612 digits). MIN = 0.01 seconds. MAX = 1 second.  
[Stored in volatile memory]  
FREQuency:APERture? [MINimum|MAXimum]  
Query the aperture time for frequency measurements.  
PERiod:APERture {0.01|0.1|1|MINimum|MAXimum}  
Select the aperture time (or gate time) for period measurements  
(the default is 0.1 seconds). Specify 10 ms (412 digits), 100 m s (default;  
512 digits), or 1 second (612 digits). MIN = 0.01 seconds. MAX = 1 second.  
[Stored in volatile memory]  
PERiod:APERture? [MINimum|MAXimum]  
Query the aperture time for period measurements.  
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[SENSe:]DETector:BANDwidth {3|20|200|MINimum|MAXimum}  
Specify the lowest frequency expected in the input signal. The multimeter  
selects the slow, medium (default), or fast ac filter based on the frequency  
you specify. MIN = 3 Hz. MAX = 200 Hz. [Stored in volatile memory]  
[SENSe:]DETector:BANDwidth? [MINimum|MAXimum]  
Query the ac filter. Returns +3.000000E+00, “+2.000000E+01, or  
+2.000000E+02.  
[SENSe:]ZERO:AUTO {OFF|ONCE|ON}  
Disable or enable (default) the autozero mode. The OFF and ONCE  
parameters have a similar effect. Autozero OFF does not issue a new  
zero measurement until the next time the multimeter goes to the  
wait-for-trigger” state. Autozero ONCE issues an immediate zero  
measurement. [Stored in volatile memory]  
[SENSe:]ZERO:AUTO?  
Query the autozero mode. Returns 0” (OFF or ONCE) or 1” (ON).  
4
INPut:IMPedance:AUTO {OFF|ON}  
Disable or enable the automatic input resistance mode for dc voltage  
measurements. With AUTO OFF (default), the input resistance is fixed  
at 10 Mfor all ranges. With AUTO ON, the input resistance is set to  
>10 Gfor the 100 mV, 1 V, and 10 V ranges. [Stored in volatile memory]  
INPut:IMPedance:AUTO?  
Query the input resistance mode. Returns 0 (OFF) or 1” (ON).  
ROUTe:TERMinals?  
Query the multimeter to determine if the front or rear input terminals  
are selected. Returns FRON” or REAR.  
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Math Operation Commands  
Math Operation Commands  
See also Math Operations,” starting on page 63 in chapter 3.  
There are five math operations available, only one of which can be  
enabled at a time. Each math operation performs a mathematical  
operation on each reading or stores data on a series of readings.  
The selected math operation remains in effect until you disable it,  
change functions, turn off the power, or perform a remote interface  
reset. The math operations use one or more internal registers. You can  
preset the values in some of the registers, while others hold the results  
of the math operation.  
The following table shows the math/measurement function combinations  
allowed. Each X” indicates an allowable combination. If you choose a  
math operation that is not allowed with the present measurement  
function, math is turned off. If you select a valid math operation and  
then change to one that is invalid, a Settings conflict” error is generated  
over the remote interface. For null and dB measurements, you must turn  
on the math operation before writing to their math registers.  
2W  
4W  
DC V AC V DC I  
AC I  
Freq  
Per  
Cont  
Diode Ratio  
X
X
X
X
X
X
X
X
X
X
X
Null  
Min-Max  
dB  
dBm  
Limit  
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
CALCulate:FUNCtion {NULL|DB|DBM|AVERage|LIMit}  
Select the math function. Only one function can be enabled at a time.  
The default function is null. [Stored in volatile memory]  
CALCulate:FUNCtion?  
Query the present math function. Returns NULL, DB, DBM, AVER, or LIM.  
CALCulate:STATe {OFF|ON}  
Disable or enable the selected math function. [Stored in volatile memory]  
CALCulate:STATe?  
Query the state of the math function. Returns 0 (OFF) or 1” (ON).  
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CALCulate:AVERage:MINimum?  
Read the minimum value found during a min-max operation. The  
multimeter clears the value when min-max is turned on, when power  
has been off, or after a remote interface reset. [Stored in volatile memory]  
CALCulate:AVERage:MAXimum?  
Read the maximum value found during a min-max operation. The  
multimeter clears the value when min-max is turned on, when power  
has been off, or after a remote interface reset. [Stored in volatile memory]  
CALCulate:AVERage:AVERage?  
Read the average of all readings taken since min-max was enabled.  
The multimeter clears the value when min-max is turned on, when  
power has been off, or after a remote interface reset. [Stored in volatile  
memory]  
CALCulate:AVERage:COUNt?  
Read the number of readings taken since min-max was enabled. The  
multimeter clears the value when min-max is turned on, when power  
has been off, or after a remote interface reset. [Stored in volatile  
memory]  
4
CALCulate:NULL:OFFSet {<value>|MINimum|MAXimum}  
Store a null value in the multimeters Null Register. You must turn on  
the math operation before writing to the math register. You can set the  
null value to any number between 0 and ±120% of the highest range,  
for the present function. MIN = –120% of the highest range. MAX = 120%  
of the highest range. [Stored in volatile memory]  
CALCulate:NULL:OFFSet? [MINimum|MAXimum]  
Query the null value.  
CALCulate:DB:REFerence {<value>|MINimum|MAXimum}  
Store a relative value in the dB Relative Register. You must turn on the  
math operation before writing to the math register. You can set the  
relative value to any number between 0 dBm and ±200 dBm.  
MIN = –200.00 dBm. MAX = 200.00 dBm. [Stored in volatile memory]  
CALCulate:DB:REFerence? [MINimum|MAXimum]  
Query the dB relative value.  
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Math Operation Commands  
CALCulate:DBM:REFerence {<value>|MINimum|MAXimum}  
Select the dBm reference value. Choose from: 50, 75, 93, 110, 124, 125,  
135, 150, 250, 300, 500, 600, 800, 900, 1000, 1200, or 8000 ohms.  
MIN = 50 . MAX = 8000 . [Stored in non-volatile memory]  
CALCulate:DBM:REFerence? [MINimum|MAXimum]  
Query the dBm reference resistance.  
CALCulate:LIMit:LOWer {<value>|MINimum|MAXimum}  
Set the lower limit for limit testing. You can set the value to any number  
between 0 and ±120% of the highest range, for the present function.  
MIN = –120% of the highest range. MAX = 120% of the highest range.  
[Stored in volatile memory]  
CALCulate:LIMit:LOWer? [MINimum|MAXimum]  
Query the lower limit.  
CALCulate:LIMit:UPPer {<value>|MINimum|MAXimum}  
Set the lower limit for limit testing. You can set the value to any number  
between 0 and ±120% of the highest range, for the present function.  
MIN = –120% of the highest range. MAX = 120% of the highest range.  
[Stored in volatile memory]  
CALCulate:LIMit:UPPer? [MINimum|MAXimum]  
Query the upper limit.  
DATA:FEED RDG_STORE, {"CALCulate"|""}  
Selects whether readings taken using the INITiatecommand are  
stored in the multimeters internal memory (default) or not stored at all.  
In the default state (DATA:FEED RDG_STORE, "CALC"), up to  
512 readings are stored in memory when INITiateis executed.  
The MEASure?and CONFigurecommands automatically select "CALC".  
With memory disabled (DATA:FEED RDG_STORE, ""), readings taken  
using INITiateare not stored. This may be useful with the min-max  
operation since it allows you to determine an average of the readings  
without storing the individual values. An error will be generated if you  
attempt to transfer readings to the output buffer using the FETCh?command.  
DATA:FEED?  
Query the reading memory state. Returns "CALC"or "".  
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Triggering  
Triggering  
See also Triggering,” starting on page 71 in chapter 3.  
First-time  
SCPI users,  
see page 154.  
The multimeters triggering system allows you to generate triggers  
either manually or automatically, take multiple readings per trigger,  
and insert a delay before each reading. Normally, the multimeter will  
take one reading each time it receives a trigger, but you can specify  
multiple readings (up to 50,000) per trigger.  
Triggering the multimeter from the remote interface is a multi-step  
process that offers triggering flexibility.  
First, you must configure the multimeter for the measurement by  
selecting the function, range, resolution, etc.  
Then, you must specify the source from which the multimeter will  
accept the trigger. The multimeter will accept a software (bus) trigger  
from the remote interface, a hardware trigger from the rear-panel  
Ext Trig (external trigger) terminal, or an immediate internal trigger.  
4
Then, you must make sure that the multimeter is ready to accept  
a trigger from the specified trigger source (this is called the wait-for-  
trigger state).  
The diagram on the next page shows the multimeters triggering system.  
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Triggering  
Agilen t 34401A Tr igger in g System  
Idle  
State  
Initiate Triggering  
MEASure?  
READ?  
INITiate  
Wait-for-  
Trigger  
State  
Trigger Source  
TRIGger:SOURce IMMediate  
TRIGger:SOURce EXTernal  
TRIGger:SOURce BUS  
Front-panel “Single” key  
Trigger Delay  
TRIGger:DELay  
Delay  
Sample ( )  
Annunciator  
Measurement  
Sample  
Sample  
Trigger  
Count 1 Count 1  
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Triggering  
Th e Wa it -for -Tr igger Sta t e  
After you have configured the multimeter and selected a trigger source,  
you must place the multimeter in the wait-for-trigger state. A trigger  
will not be accepted until the multimeter is in this state. If a trigger  
signal is present, and if multimeter is in the wait-for-trigger” state,  
the measurement sequence begins and readings are taken.  
The wait-for-trigger” state is a term used primarily for remote interface  
operation. From the front panel, the multimeter is always in the wait-  
for-trigger” state and will accept triggers at any time, unless a  
measurement is already in progress.  
You can place the multimeter in the wait-for-trigger” state by executing  
any of the following commands from the remote interface.  
MEASure?  
READ?  
INITiate  
4
The multimeter requires approximately 20 ms of set-up time after you  
send a command to change to the wait-for-trigger” state. Any external  
triggers that occur during this set-up time are ignored.  
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Triggering Commands  
Triggering Commands  
See also Triggering,” starting on page 71 in chapter 3.  
INITiate  
Change the state of the triggering system from the idle” state to the  
wait-for-trigger” state. Measurements will begin when the specified  
trigger conditions are satisfied after the INITiatecommand is  
received. The readings are placed in the multimeters internal memory  
(up to 512 readings can be stored). Readings are stored in memory until  
you are able to retrieve them. Use the FETCh?command to retrieve  
reading results.  
A new command is available starting with firmware Revision 2 which  
allows you to take readings using INITiatewithout storing them in  
internal memory. This command may be useful with the min-max  
operation since it allows you to determine the average of a series of  
readings without storing the individual values.  
DATA:FEED RDG_STORE, ""  
DATA:FEED RDG_STORE, "CALCulate"  
do not store readings  
store readings (default)  
See page 126 for more information on using the DATA:FEEDcommand.  
READ?  
Change the state of the trigger system from the idle” state to the  
wait-for-trigger” state. Measurements will begin when the specified  
trigger conditions are satisfied following the receipt of the READ?  
command. Readings are sent immediately to the output buffer.  
TRIGger:SOURce {BUS|IMMediate|EXTernal}  
Select the source from which the multimeter will accept a trigger.  
The multimeter will accept a software (bus) trigger, an immediate  
internal trigger (this is the default source), or a hardware trigger from the  
rear-panel Ext Trig (external trigger) terminal. [Stored in volatile memory]  
TRIGger:SOURce?  
Query the present trigger source. Returns BUS, “IMM, or EXT.  
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TRIGger:DELay {<seconds>|MINimum|MAXimum}  
Insert a trigger delay between the trigger signal and each sample  
that follows. If you do not specify a trigger delay, the multimeter  
automatically selects a delay for you. Select from 0 to 3600 seconds.  
MIN = 0 seconds. MAX = 3600 seconds. [Stored in volatile memory]  
TRIGger:DELay? [MINimum|MAXimum]  
Query the trigger delay.  
TRIGger:DELay:AUTO {OFF|ON}  
Disable or enable an automatic trigger delay. The delay is determined  
by function, range, integration time, and ac filter setting. Selecting a  
specific trigger delay value automatically turns off the automatic trigger  
delay. [Stored in volatile memory]  
TRIGger:DELay:AUTO?  
Query the automatic trigger delay setting. Returns 0” (OFF) or “1 (ON).  
4
SAMPle:COUNt {<value>|MINimum|MAXimum}  
Set the number of readings (samples) the multimeter takes per trigger.  
Select from 1 to 50,000 readings per trigger. MIN = 1. MAX = 50,000.  
[Stored in volatile memory]  
SAMPle:COUNt? [MINimum|MAXimum]  
Query the sample count.  
TRIGger:COUNt {<value>|MINimum|MAXimum|INFinite}  
Set the number of triggers the multimeter will accept before returning  
to the idle” state. Select from 1 to 50,000 triggers. The INFinite  
parameter instructs the multimeter to continuously accept triggers  
(you must send a device clear to return to the idle” state). Trigger count  
is ignored while in local operation. MIN = 1. MAX = 50,000.  
[Stored in volatile memory]  
TRIGger:COUNt? [MINimum|MAXimum]  
Query the trigger count. If you specify an infinite trigger count,  
the query command returns 9.90000000E+37.  
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System-Related Commands  
System-Related Commands  
See also System-Related Operations,” starting on page 84 in chapter 3.  
FETCh?  
Transfer readings stored in the multimeters internal memory by the  
INITiatecommand to the multimeters output buffer where you can  
read them into your bus controller.  
READ?  
Change the state of the trigger system from the idle” state to the  
wait-for-trigger” state. Measurements will begin when the specified  
trigger conditions are satisfied following the receipt of the READ?  
command. Readings are sent immediately to the output buffer.  
DISPlay {OFF|ON}  
Turn the front-panel display off or on. [Stored in volatile memory]  
DISPlay?  
Query the front-panel display setting. Returns 0” (OFF) or 1” (ON).  
DISPlay:TEXT <quoted string>  
Display a message on the front panel. The multimeter will display up to  
12 characters in a message; any additional characters are truncated.  
[Stored in volatile memory]  
DISPlay:TEXT?  
Query the message sent to the front panel and return a quoted string.  
DISPlay:TEXT:CLEar  
Clear the message displayed on the front panel.  
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System-Related Commands  
SYSTem:BEEPer  
Issue a single beep immediately.  
SYSTem:BEEPer:STATe {OFF|ON}  
Disable or enable the front-panel beeper. [Stored in non-volatile memory]  
When you disable the beeper, the multimeter will not emit a tone when:  
1) a new minimum or maximum is found in a min–max test.  
2) a stable reading is captured in reading hold.  
3) a limit is exceeded in a limit test.  
4) a forward-biased diode is measured in the diode test function.  
SYSTem:BEEPer:STATe?  
Query the state of the front-panel beeper. Returns 0 (OFF) or 1” (ON).  
SYSTem:ERRor?  
Query the multimeters error queue. Up to 20 errors can be stored in the  
queue. Errors are retrieved in first-in-first out (FIFO) order. Each error  
string may contain up to 80 characters.  
4
SYSTem:VERSion?  
Query the multimeter to determine the present SCPI version.  
DATA:POINts?  
Query the number of readings stored in the multimeters internal memory.  
*RST  
Reset the multimeter to its power-on configuration.  
*TST?  
Perform a complete self-test of the multimeter. Returns 0 if the  
self-test is successful, or 1 if it test fails.  
*IDN?  
Read the multimeters identification string (be sure to dimension a  
string variable with at least 35 characters).  
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The SCPI Status Model  
The SCPI Status Model  
All SCPI instruments implement status registers in the same way.  
The status system records various instrument conditions in three  
register groups: the Status Byte register, the Standard Event register,  
and the Questionable Data register. The status byte register records  
high-level summary information reported in the other register groups.  
The diagram on the next page illustrates the SCPI status system.  
Chapter 6, Application Programs,” contains an example program  
showing the use of the status registers. You may find it useful to refer  
to the program after reading the following section in this chapter.  
Wh a t is a n Even t Regist er ?  
The standard event and questionable data registers have event registers.  
An event register is a read-only register that reports defined conditions  
within the multimeter. Bits in the event registers are latched. Once an  
event bit is set, subsequent state changes are ignored. Bits in an event  
register are automatically cleared by a query of that register (such as  
*ESR?or STAT:QUES:EVEN?) or by sending the *CLS(clear status)  
command. A reset (*RST) or device clear will not clear bits in event  
registers. Querying an event register returns a decimal value which  
corresponds to the binary-weighted sum of all bits set in the register.  
Wh a t is a n En a ble R egist er ?  
An enable register defines which bits in the corresponding event register  
are logically ORed together to form a single summary bit. Enable  
registers are both readable and writable. Querying an enable register  
will not clear it. The *CLS(clear status) command does not clear  
enable registers but it does clear the bits in the event registers.  
The STATus:PRESetcommand will clear the questionable data enable  
register. To enable bits in an enable register, you must write a decimal  
value which corresponds to the binary-weighted sum of the bits you  
wish to enable in the register.  
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The SCPI Status Model  
SCP I Sta tu s System  
4
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The SCPI Status Model  
Th e St a tu s Byte  
The status byte summary register reports conditions from other status  
registers. Query data that is waiting in the multimeters output buffer is  
immediately reported through the message available” bit (bit 4). Bits in  
the summary registers are not latched. Clearing an event register will  
clear the corresponding bits in the status byte summary register.  
Reading all messages in the output buffer, including any pending  
queries, will clear the message available bit.  
Bit Definitions – Status Byte Register  
Decimal  
Bit  
Definition  
Always set to 0.  
Always set to 0.  
Always set to 0.  
One or more bits are set in the Questionable Data  
register (bits must be “enabled” in enable register).  
Data is available in the multimeter’s output buffer.  
One or more bits are set in the Standard Event  
register (bits must be “enabled” in enable register).  
The multimeter is requesting service (serial poll).  
Always set to 0.  
Value  
0 Not Used  
1 Not Used  
2 Not Used  
3 Questionable Data  
1
2
4
8
4 Message Available  
5 Standard Event  
16  
32  
6 Request Service  
7 Not Used  
64  
128  
The status byte summary register is cleared when:  
You execute a *CLS(clear status) command.  
Querying the standard event and questionable data registers will  
clear only the respective bits in the summary register.  
The status byte enable register (request service) is cleared when:  
You turn on the power and you have previously configured the  
multimeter using the *PSC 1command.  
You execute a *SRE 0command.  
The status byte enable register will not be cleared at power-on if you  
have previously configured the multimeter using *PSC 0.  
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The SCPI Status Model  
Usin g Ser vice Requ est (SRQ) a n d Ser ia l P OLL  
You must configure your bus controller to respond to the IEEE-488  
service request (SRQ) interrupt to use this capability. Use the status  
byte enable register (SRE) to select which summary bits will set the  
low-level IEEE-488 SRQ signal. When the status byte request service”  
bit (bit 6) is set, an IEEE-488 SRQ interrupt message is automatically  
sent to the bus controller. The bus controller may then poll the  
instruments on the bus to identify which one requested service (the one  
with bit 6 set in its status byte). The request service bit is only cleared  
by reading the status byte using an IEEE-488 serial poll or by reading  
the event register whose summary bit is causing the service request.  
To read the status byte summary register, send the IEEE-488 serial poll  
message. Querying the summary register will return a decimal value  
which corresponds to the binary-weighted sum of the bits set in the  
register. Serial poll will automatically clear the request service” bit in  
the status byte summary register. No other bits are affected. Performing  
a serial poll will not affect instrument throughput.  
4
C a u t i o n  
The IEEE-488.2 standard does not ensure synchronization between your  
bus controller program and the instrument. Use the *OPC? command to  
guarantee that commands previously sent to the instrument have  
completed. Executing a serial poll before a *RST, *CLS, or other  
commands have completed can cause previous conditions to be reported.  
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The SCPI Status Model  
Usin g *STB? t o Rea d th e St a tu s Byte  
The *STB?(status byte query) command is similar to a serial poll except  
it is processed like any other instrument command. The *STB?command  
returns the same result as an IEEE-488 serial poll except that the  
request service” bit (bit 6) is not cleared if a serial poll has occurred.  
The *STB?command is not handled automatically by the IEEE-488 bus  
interface hardware and the command will be executed only after  
previous commands have completed. Polling is not possible using the  
*STB?command. Using the *STB?command does not clear the status  
byte summary register.  
To In ter r u pt You r Bu s Con tr oller Usin g SRQ  
Send a bus device clear message.  
Clear the event registers with the *CLS(clear status) command.  
Set the *ESE(standard event register) and *SRE(status byte  
register) enable masks.  
Send the *OPC?(operation complete query) command and enter the  
result to assure synchronization.  
Enable your bus controllers IEEE-488 SRQ interrupt.  
To Deter m in e Wh en a Com m an d Sequ en ce is Com p leted  
Send a device clear message to clear the multimeters output buffer.  
Clear the event registers with the *CLS(clear status) command.  
Enable operation complete” using the *ESE 1command (standard  
event register).  
Send the *OPC?(operation complete query) command and enter the  
result to assure synchronization.  
Send your programming command string, and place the *OPC  
(operation complete) command as the last command.  
Use a serial poll to check to see when bit 5 (standard event) is set  
in the status byte summary register. You could also configure the  
multimeter for an SRQ interrupt by sending *SRE 32(status byte  
enable register, bit 5).  
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How to Use th e Message Available Bit (MAV)  
You can use the status byte message available” bit (bit 4) to determine  
when data becomes available to read into your bus controller. The  
multimeter sets bit 4 when the first reading trigger occurs (which can be  
TRIGger:SOURce:IMMediate). The multimeter subsequently clears  
bit 4 only after all messages have been read from the output buffer.  
The message available (MAV) bit can only indicate when the first  
reading is available following a READ?command. This can be helpful if  
you do not know when a trigger event such as BUSor EXTernalwill occur.  
The MAV bit is set only after all specified measurements have completed  
when using the INITiatecommand followed by FETCh?. Readings are  
placed in the multimeters internal memory when using INITiate.  
Sending the FETCh?command transfers readings (stored in internal  
memory by the INITiatecommand) to the multimeters output buffer.  
Therefore, the MAV bit can only be set after all measurements have  
been completed.  
4
Usin g *OP C to Sign a l Wh en Data is in th e Ou tp u t Bu ffer  
Generally, it is best to use the operation complete” bit (bit 0) in the  
standard event register to signal when a command sequence is  
completed. This bit is set in the register after an *OPCcommand has  
been executed. If you send *OPC after a command which loads a message  
in the multimeters output buffer (either reading data or query data),  
you can use the operation complete bit to determine when the message  
is available. However, if too many messages are generated before the  
*OPCcommand executes (sequentially), the output buffer will fill and  
the multimeter will stop taking readings.  
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Th e St a n d a r d Even t R egist er  
The standard event register reports the following types of instrument  
events: power-on detected, command syntax errors, command execution  
errors, self-test or calibration errors, query errors, or when an *OPC  
command is executed. Any or all of these conditions can be reported in  
the standard event summary bit through the enable register. You must  
write a decimal value using the *ESE(event status enable) command to  
set the enable register mask.  
An error condition (standard event register bits 2, 3, 4, or 5) will always  
record one or more errors in the multimeters error queue, except for the  
following case. Read the error queue using SYSTem:ERRor?.  
A reading overload condition is always reported in both the standard event  
register (bit 3) and the questionable data event register (bits 0, 1, or 9).  
However, no error message is recorded in the multimeters error queue.  
Bit Definitions – Standard Event Register  
Decimal  
Bit  
Definition  
Value  
0 Operation Complete  
1
All commands prior to and including an *OPC  
command have been executed.  
1 Not Used  
2 Query Error  
2
4
Always set to 0.  
The multimeter tried to read the output buffer but  
it was empty. Or, a new command line was  
received before a previous query has been read.  
Or, both the input and output buffers are full.  
A self-test, calibration, or reading overload error  
occurred (see error numbers 501 through 748 in  
chapter 5).  
3 Device Error  
8
4 Execution Error  
5 Command Error  
16  
32  
An execution error occurred (see error numbers  
-211 through -230 in chapter 5).  
A command syntax error occurred (see error  
numbers -101 through -158 in chapter 5).  
Always set to 0.  
6 Not Used  
7 Power On  
64  
128  
Power has been turned off and on since the last  
time the event register was read or cleared.  
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The standard event register is cleared when:  
You send a *CLS (clear status) command.  
You query the event register using the *ESR?(event status register)  
command.  
The standard event enable register is cleared when:  
You turn on the power and you have previously configured the  
multimeter using the *PSC 1 command.  
You execute a *ESE 0command.  
The standard event enable register will not be cleared at power-on if you  
have previously configured the multimeter using *PSC 0.  
4
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Th e Qu estion a b le Da t a Register  
The questionable data register provides information about the quality  
of the multimeters measurement results. Overload conditions and  
high/low limit test results are reported. Any or all of these conditions  
can be reported in the questionable data summary bit through the  
enable register. You must write a decimal value using the STATus:  
QUEStionable:ENABlecommand to set the enable register mask.  
Note: A reading overload condition is always reported in both the  
standard event register (bit 3) and the questionable data event register  
(bits 0, 1, or 9). However, no error messa ge is recorded in the  
multimeters error queue.  
Bit Definitions – Questionable Data Register  
Decimal  
Bit  
Definition  
Value  
0 Voltage Overload  
Range overload on dc volts, ac volts,  
frequency, period, diode, or ratio function.  
Range overload on dc or ac current function.  
Always set to 0.  
1
1 Current Overload  
2 Not Used  
2
4
3 Not Used  
Always set to 0.  
8
4 Not Used  
Always set to 0.  
16  
5 Not Used  
Always set to 0.  
32  
6 Not Used  
Always set to 0.  
64  
7 Not Used  
8 Not Used  
Always set to 0.  
Always set to 0.  
128  
256  
512  
1024  
2048  
4096  
8192  
16384  
32768  
9 Ohms Overload  
10 Not Used  
11 Limit Fail LO  
12 Limit Fail HI  
13 Not Used  
14 Not Used  
15 Not Used  
Range overload on 2-wire or 4-wire ohms.  
Always set to 0.  
Reading is less than lower limit in limit test.  
Reading exceeds upper limit in limit test.  
Always set to 0.  
Always set to 0.  
Always set to 0.  
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The SCPI Status Model  
The questionable data event register is cleared when:  
You execute a *CLS(clear status) command.  
You query the event register using STATus:QUEStionable:EVENt?.  
The questionable data enable register is cleared when:  
You turn on the power (*PSCdoes not apply).  
You execute the STATus:PRESetcommand.  
You execute the STATus:QUEStionable:ENABle 0 command.  
4
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Status Reporting Commands  
Status Reporting Commands  
SYSTem:ERRor?  
Query the multimeters error queue. Up to 20 errors can be stored in the  
queue. Errors are retrieved in first-in-first out (FIFO) order. Each error  
string may contain up to 80 characters.  
STATus:QUEStionable:ENABle <enable value>  
Enable bits in the Questionable Data enable register. The selected bits  
are then reported to the Status Byte.  
STATus:QUEStionable:ENABle?  
Query the Questionable Data enable register. The multimeter returns a  
binary-weighted decimal representing the bits set in the enable register.  
STATus:QUEStionable:EVENt?  
Query the Questionable Data event register. The multimeter returns a  
decimal value which corresponds to the binary-weighted sum of all bits  
set in the register.  
STATus:PRESet  
Clear all bits in the Questionable Data enable register.  
*CLS  
Clear the Status Byte summary register and all event registers.  
*ESE <enable value>  
Enable bits in the Standard Event enable register. The selected bits are  
then reported to the Status Byte.  
*ESE?  
Query the Standard Event enable register. The multimeter returns a  
decimal value which corresponds to the binary-weighted sum of all bits  
set in the register.  
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Status Reporting Commands  
*ESR?  
Query the Standard event register. The multimeter returns a decimal  
value which corresponds to the binary-weighted sum of all bits set in the  
register.  
*OPC  
Sets the operation complete” bit (bit 0) in the Standard Event register  
after the command is executed.  
*OPC?  
Returns 1 to the output buffer after the command is executed.  
*PSC {0|1}  
Power-on status clear. Clear the Status Byte and Standard Event  
register enable masks when power is turned on (*PSC 1). When *PSC 0  
is in effect, the Status Byte and Standard Event register enable masks  
are not cleared when power is turned on. [Stored in non-volatile memory]  
4
*PSC?  
Query the power-on status clear setting. Returns 0 (*PSC 0) or  
1” (*PSC 1).  
*SRE <enable value>  
Enable bits in the Status Byte enable register.  
*SRE?  
Query the Status Byte enable register. The multimeter returns a  
decimal value which corresponds to the binary-weighted sum of all bits  
set in the register.  
*STB?  
Query the Status Byte summary register. The *STB?command is  
similar to a serial poll but it is processed like any other instrument  
command. The *STB?command returns the same result as a serial  
poll but the request service” bit (bit 6) is not cleared if a serial poll  
has occurred.  
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Calibration Commands  
Calibration Commands  
See Calibration Overview” starting on page 95 for an overview of the  
calibration features of the multimeter. For a more detailed discussion  
of the calibration procedures, see chapter 4 in the Service Guide.  
CALibration?  
Perform a calibration using the specified calibration value  
(CALibration:VALuecommand). Before you can calibrate the  
multimeter, you must unsecure it by entering the correct security code.  
CALibration:COUNt?  
Query the multimeter to determine the number of times it has been  
calibrated. Your multimeter was calibrated before it left the factory.  
When you receive your multimeter, read the count to determine its  
initial value. [Stored in non-volatile memory]  
The calibration count increments up to a maximum of 32,767 after  
which it wraps-around to 0. Since the value increments by one for  
each calibration point, a complete calibration will increase the value  
by many counts.  
CALibration:SECure:CODE <new code>  
Enter a new security code. To change the security code, you must first  
unsecure the multimeter using the old security code, and then enter a  
new code. The calibration code may contain up to 12 characters.  
[Stored in non-volatile memory]  
CALibration:SECure:STATe {OFF|ON},<code>  
Unsecure or secure the multimeter for calibration. The calibration code  
may contain up to 12 characters. [Stored in non-volatile memory]  
CALibration:SECure:STATe?  
Query the secured state of the multimeter. Returns 0” (OFF) or “1 (ON).  
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Calibration Commands  
CALibration:STRing <quoted string>  
Record calibration information about your multimeter. For example,  
you can store such information as the last calibration date, the next  
calibration due date, the instrument serial number, or even the name  
and phone number of the person to contact for a new calibration.  
[Stored in non-volatile memory]  
You can record information in the calibration message only from the  
remote interface. However, you can read the message from either the  
front-panel menu or the remote interface.  
The calibration message may contain up to 40 characters. However,  
the multimeter can display only 12 characters of the message on the  
front panel (additional characters are truncated).  
CALibration:STRing?  
Query the calibration message and return a quoted string.  
CALibration:VALue <value>  
Specify the value of the known calibration signal used by the calibration  
4
procedure.  
CALibration:VALue?  
Query the present calibration value.  
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RS-232 Interface Configuration  
RS-232 Interface Configuration  
See also Remote Interface Configuration,” on page 91 in chapter 3.  
You connect the multimeter to the RS-232 interface using the 9-pin (DB-9)  
serial connector on the rear panel. The multimeter is configured as a  
DTE (Data Terminal Equipment) device. For all communications over  
the RS-232 interface, the multimeter uses two handshake lines:  
DTR (Data Terminal Ready) on pin 4 and DSR (Data Set Ready) on pin 6.  
The following sections contain information to help you use the  
multimeter over the RS-232 interface. The programming commands  
for RS-232 are listed on page 153.  
RS-232 Con figu r a t ion Over view  
Configure the RS-232 interface using the parameters shown below.  
Use the front-panel I/O MENU to select the baud rate, parity, and  
number of data bits (see also pages 163 and 164 for more information).  
Baud Rate: 300, 600, 1200, 2400, 4800, or 9600 baud (factory setting)  
Parity and Data Bits: None / 8 data bits  
Even / 7 data bits, (factory setting) or  
Odd / 7 data bits  
Number of Start Bits: 1 bit (fixed)  
Number of Stop Bits: 2 bits (fixed)  
C a u t i o n  
Do not use the RS-232 interface if you have configured the multimeter to  
output pass/ fail signals on pins 1 and 9. Internal components on the  
RS-232 interface circuitry may be damaged.  
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RS-232 Interface Configuration  
RS-232 Da ta F r a m e F or m a t  
A character frame consists of all the transmitted bits that make up a  
single character. The frame is defined as the characters from the start bit  
to the last stop bit, inclusively. Within the frame, you can select the  
baud rate, number of data bits, and parity type. The multimeter uses  
the following frame formats for seven and eight data bits.  
Con n ection t o a Com p u t er or Ter m in a l  
4
To connect the multimeter to a computer or terminal, you must have  
the proper interface cable. Most computers and terminals are DTE  
(Data Terminal Equipment) devices. Since the multimeter is also a DTE  
device, you must use a DTE-to-DTE interface cable. These cables are also  
called null-modem, modem-eliminator, or crossover cables.  
The interface cable must also have the proper connector on each end  
and the internal wiring must be correct. Connectors typically have  
9 pins (DB-9 connector) or 25 pins (DB-25 connector) with a male”  
or female” pin configuration. A male connector has pins inside the  
connector shell and a female connector has holes inside the connector shell.  
If you cannot find the correct cable for your configuration, you may  
have to use a wiring adapter. If you are using a DTE-to-DTE cable, make  
sure the adapter is a straight-through” type. Typical adapters include  
gender changers, null-modem adapters, and DB-9 to DB-25 adapters.  
Refer to the cable and adapter diagrams on the following page to  
connect the multimeter to most computers or terminals. If your  
configuration is different than those described, order the Agilent 34399A  
Adapter Kit. This kit contains adapters for connection to other  
computers, terminals, and modems. Instructions and pin diagrams are  
included with the adapter kit.  
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RS-232 Interface Configuration  
DB-9 Ser ia l Con n ection If your computer or terminal has a 9-pin  
serial port with a male connector, use the null-modem cable included  
with the Agilent 34398A Cable Kit. This cable has a 9-pin female  
connector on each end. The cable pin diagram is shown below.  
DB-25 Ser ia l Con n ection If your computer or terminal has a 25-pin  
serial port with a male connector, use the null-modem cable and 25-pin  
adapter included with the Agilent 34398A Cable Kit. The cable and  
adapter pin diagram is shown below.  
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RS-232 Interface Configuration  
DTR / DSR Ha n d sh a k e P r otocol  
The multimeter is configured as a DTE (Data Terminal Equipment) device  
and uses the DTR (Data Terminal Ready) and DSR (Data Set Ready) lines  
of the RS-232 interface to handshake. The multimeter uses the DTR line  
to send a hold-off signal. The DTR line must be TRUE before the  
multimeter will accept data from the interface. When the multimeter  
sets the DTR line FALSE, the data must cease within 10 characters.  
To disable the DTR/DSR handshake, do not connect the DTR line and tie  
the DSR line to logic TRUE. If you disable the DTR/DSR handshake,  
also select a slower baud rate (300, 600, or 1200 baud) to ensure that  
the data is transmitted correctly.  
The multimeter sets the DTR line FALSE in the following cases:  
1 When the multimeters input buffer is full (when approximately  
100 characters have been received), it sets the DTR line FALSE (pin 4 on  
the RS-232 connector). When enough characters have been removed to  
make space in the input buffer, the multimeter sets the DTR line TRUE,  
unless the second case (see below) prevents this.  
4
2 When the multimeter wants to talk” over the interface (which means  
that it has processed a query) and has received a <new line> message  
terminator, it will set the DTR line FALSE. This implies that once a  
query has been sent to the multimeter, the controller should read the  
response before attempting to send more data. It also means that a  
<new line> must terminate the command string. After the response has  
been output, the multimeter sets the DTR line TRUE again, unless the  
first case (see above) prevents this.  
The multimeter monitors the DSR line to determine when the controller  
is ready to accept data over the interface. The multimeter monitors the  
DSR line (pin 6 on the RS-232 connector) before each character is sent.  
The output is suspended if the DSR line is FALSE. When the DSR line  
goes TRUE, transmission will resume.  
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RS-232 Interface Configuration  
The multimeter holds the DTR line FALSE while output is suspended.  
A form of interface deadlock exists until the controller asserts the DSR  
line TRUE to allow the multimeter to complete the transmission.  
You can break the interface deadlock by sending the <Ctrl-C> character,  
which clears the operation in progress and discards pending output  
(this is equivalent to the IEEE-488 device clear action). For the <Ctrl-C>  
character to be recognized reliably by the multimeter while it holds DTR  
FALSE, the controller must first set DSR FALSE.  
In addition, you may have difficulty sending the <Ctrl-C> character if  
you are interrupting a query operation, in which case the multimeter  
hold the DTR line FALSE. This may prevent the controller from sending  
anything unless you first reprogram the interface to ignore DTR.  
RS-232 Tr ou blesh ootin g  
Here are a few things to check if you are having problems communicating  
over the RS-232 interface. If you need additional help, refer to the  
documentation that came with your computer.  
Verify that the multimeter and your computer are configured for the  
same baud rate, parity, and number of data bits. Make sure that your  
computer is set up for 1 start bit and 2 stop bits (these values are fixed  
on the multimeter).  
Make sure to execute the SYSTem:REMotecommand to place the  
multimeter in the REMOTE mode.  
Verify that you have connected the correct interface cable and adapters.  
Even if the cable has the proper connectors for your system, the  
internal wiring may not be correct. The Agilent 34398A Cable Kit can  
be used to connect the multimeter to most computers or terminals.  
Verify that you have connected the interface cable to the correct  
serial port on your computer (COM1, COM2, etc).  
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RS-232 Interface Commands  
RS-232 Interface Commands  
Use the front-panel I/ O MENU to select the baud rate, parity, and  
number of data bits (see pages 163 and 164 for more information).  
SYSTem:LOCal  
Place the multimeter in the local mode for RS-232 operation. All keys on  
the front panel are fully functional.  
SYSTem:REMote  
Place the multimeter in the remote mode for RS-232 operation.  
All keys on the front panel, except the LOCAL key, are disabled.  
4
It is very important that you send the SYSTem:REMote command  
to place the multimeter in the remote mode. Sending or receiving data  
over the RS-232 interface when not configured for remote operation can  
cause unpredictable results.  
SYSTem:RWLock  
Place the multimeter in the remote mode for RS-232 operation.  
This command is the same as the SYSTem:REMotecommand except  
that all keys on the front panel are disabled, including the LOCAL key.  
Ctrl-C  
Clear the operation in progress over the RS-232 interface and discard  
any pending output data. This is equivalent to the IEEE-488 device clear  
action over the GPIB interface.  
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An Introduction to the SCPI Language  
An Introduction to the SCPI Language  
SCPI (Standard Commands for Programmable Instruments) is an  
ASCII-based instrument command language designed for test and  
measurement instruments. Refer to Simplified Programming Overview,”  
starting on page 112, for an introduction to the basic techniques used to  
program the multimeter over the remote interface.  
SCPI commands are based on a hierarchical structure, also known as a  
tree system. In this system, associated commands are grouped together  
under a common node or root, thus forming subsystems. A portion of the  
SENSEsubsystem is shown below to illustrate the tree system.  
SENSe:  
VOLTage:  
DC:RANGe {<range>|MINimum|MAXimum}  
VOLTage:  
DC:RANGe? [MINimum|MAXimum]  
FREQuency:  
VOLTage:RANGe {<range>|MINimum|MAXimum}  
FREQuency:  
VOLTage:RANGe? [MINimum|MAXimum]  
DETector:  
BANDwidth {3|20|200|MINimum|MAXimum}  
DETector:  
BANDwidth? [MINimum|MAXimum]  
ZERO:  
AUTO {OFF|ONCE|ON}  
ZERO:  
AUTO?  
SENSeis the root keyword of the command, VOLTageand FREQuency  
are second-level keywords, and DCand VOLTageare third-level  
keywords. A colon ( : ) separates a command keyword from a  
lower-level keyword.  
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An Introduction to the SCPI Language  
Com m a n d F or m a t Used in Th is Ma n u a l  
The format used to show commands in this manual is shown below:  
VOLTage:DC:RANGe {<range>|MINimum|MAXimum}  
The command syntax shows most commands (and some parameters)  
as a mixture of upper- and lower-case letters. The upper-case letters  
indicate the abbreviated spelling for the command. For shorter program  
lines, send the abbreviated form. For better program readability, send  
the long form.  
For example, in the above syntax statement, VOLTand VOLTAGE  
are both acceptable forms. You can use upper- or lower-case letters.  
Therefore, VOLTAGE, volt, and Voltare all acceptable. Other forms,  
such as VOLand VOLTAG, will generate an error.  
Braces ( { } ) enclose the parameter choices for a given command string.  
The braces are not sent with the command string.  
4
|
A vertical bar ( ) separates multiple parameter choices for a given  
command string.  
Triangle brackets ( < > ) indicate that you must specify a value for the  
enclosed parameter. For example, the above syntax statement shows  
the range parameter enclosed in triangle brackets. The brackets are not  
sent with the command string. You must specify a value for the  
parameter (such as "VOLT:DC:RANG 10").  
Some parameters are enclosed in square brackets ( [ ] ). The brackets  
indicate that the parameter is optional and can be omitted. The brackets  
are not sent with the command string. If you do not specify a value for  
an optional parameter, the multimeter chooses a default value.  
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An Introduction to the SCPI Language  
Com m a n d Sep a r a t or s  
A colon ( : ) is used to separate a command keyword from a lower-level  
keyword. You must insert a blank space to separate a parameter from a  
command keyword. If a command requires more than one parameter,  
you must separate adjacent parameters using a comma as shown below:  
"CONF:VOLT:DC 10, 0.003"  
A semicolon ( ; ) is used to separate commands within the same  
subsystem, and can also minimize typing. For example, sending the  
following command string:  
"TRIG:DELAY 1; COUNT 10"  
... is the same as sending the following two commands:  
"TRIG:DELAY 1"  
"TRIG:COUNT 10"  
Use a colon and a semicolon to link commands from different subsystems.  
For example, in the following command string, an error is generated if  
you do not use both the colon and semicolon:  
"SAMP:COUN 10;:TRIG:SOUR EXT"  
Usin g th e MIN a n d MAX P a r a m et er s  
You can substitute MINimumor MAXimumin place of a parameter for  
many commands. For example, consider the following command:  
VOLTage:DC:RANGe {<range>|MINimum|MAXimum}  
Instead of selecting a specific voltage range, you can substitute MIN  
to set the range to its minimum value or MAXto set the range to its  
maximum value.  
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An Introduction to the SCPI Language  
Qu er yin g P a r a m et er Set tin gs  
You can query the current value of most parameters by adding a  
question mark ( ? ) to the command. For example, the following  
command sets the sample count to 10 readings:  
"SAMP:COUN 10"  
You can query the sample count by executing:  
"SAMP:COUN?"  
You can also query the minimum or maximum count allowed as follows:  
"SAMP:COUN? MIN"  
"SAMP:COUN? MAX"  
4
C a u t i o n  
If you send two query commands without reading the response from the  
first, and then attempt to read the second response, you may receive some  
data from the first response followed by the complete second response.  
To avoid this, do not send a query command without reading the  
response. When you cannot avoid this situation, send a device clear  
before sending the second query command.  
SCP I Com m a n d Ter m in a t or s  
A command string sent to the multimeter must terminate with a  
<new line> character. The IEEE-488 EOI (end-or-identify) message is  
interpreted as a <new line> character and can be used to terminate a  
command string in place of a <new line> character. A <carriage return>  
followed by a <new line> is also accepted. Command string termination  
will always reset the current SCPI command path to the root level.  
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An Introduction to the SCPI Language  
IEEE-488.2 Com m on Com m a n d s  
The IEEE-488.2 standard defines a set of common commands that  
perform functions like reset, self-test, and status operations. Common  
commands always begin with an asterisk ( ), are four to five characters  
*
in length, and may include one or more parameters. The command  
keyword is separated from the first parameter by a blank space.  
Use a semicolon ( ; ) to separate multiple commands as shown below:  
"*RST; *CLS; *ESE 32; *OPC?"  
SCP I P a r a m eter Typ es  
The SCPI language defines several different data formats to be used in  
program messages and response messages.  
Nu mer ic P a r a meter s Commands that require numeric parameters  
will accept all commonly used decimal representations of numbers  
including optional signs, decimal points, and scientific notation.  
Special values for numeric parameters like MINimum, MAXimum, and  
DEFaultare also accepted. You can also send engineering unit suffixes  
with numeric parameters (e.g., M, K, or u). If only specific numeric  
values are accepted, the multimeter will automatically round the input  
numeric parameters. The following command uses a numeric parameter:  
VOLTage:DC:RANGe {<range>|MINimum|MAXimum}  
Discr ete P a r a m eter s Discrete parameters are used to program  
settings that have a limited number of values (like BUS, IMMediate,  
EXTernal). They have a short form and a long form just like command  
keywords. You can mix upper- and lower-case letters. Query responses  
will always return the short form in all upper-case letters. The following  
command uses discrete parameters:  
TRIGger:SOURce {BUS|IMMediate|EXTernal}  
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Output Data Formats  
Boolea n P a r a m eter s Boolean parameters represent a single binary  
condition that is either true or false. For a false condition, the multimeter  
will accept OFF” or 0. For a true condition, the multimeter will accept  
ON” or 1. When you query a boolean setting, the instrument will  
always return 0 or 1. The following command uses a boolean parameter:  
INPut:IMPedance:AUTO {OFF|ON}  
Str in g P a r a m eter s String parameters can contain virtually any set  
of ASCII characters. A string must begin and end with matching quotes;  
either with a single quote or with a double quote. You can include the  
quote delimiter as part of the string by typing it twice without any  
characters in between. The following command uses a string parameter:  
DISPlay:TEXT <quoted string>  
4
Output Data Formats  
Output data will be in one of formats shown in the table below.  
Type of Output Data  
Output Data Format  
Non-reading queries  
< 80 ASCII character string  
Single reading (IEEE-488)  
Multiple readings (IEEE-488)  
Single reading (RS-232)  
Multiple readings (RS-232)  
SD.DDDDDDDDESDD<nl>  
SD.DDDDDDDDESDD,...,...,<nl>  
SD.DDDDDDDDESDD<cr><nl>  
SD.DDDDDDDDESDD,...,...,<cr><nl>  
S
D
E
Negative sign or positive sign  
Numeric digits  
Exponent  
<nl> newline character  
<cr> carriage return character  
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Using Device Clear to Halt Measurements  
Using Device Clear to Halt Measurements  
Device clear is an IEEE-488 low-level bus message which can be used to  
halt measurements in progress. Different programming languages and  
IEEE-488 interface cards provide access to this capability through their  
own unique commands. The status registers, the error queue, and all  
configuration states are left unchanged when a device clear message is  
received. Device clear performs the following actions.  
All measurements in progress are aborted.  
The multimeter returns to the trigger idle state.”  
The multimeters input and output buffers are cleared.  
The multimeter is prepared to accept a new command string.  
For RS-232 operation, sending the <Ctrl-C> character will perform  
the equivalent operations of the IEEE-488 device clear message.  
The multimeters DTR (data terminal ready) handshake line will be true  
following a device clear message. See DTR/ DSR Handshake Protocol,”  
on page 151 for further details.  
TALK ONLY for Printers  
You can set the address to 31” which is the talk only mode. In this  
mode, the multimeter can output readings directly to a printer without  
being addressed by a bus controller (over either GPIB or RS-232).  
For proper operation, make sure your printer is configured in the  
listen always mode. Address 31 is not a valid address if you are  
operating the multimeter from the GPIB interface with a bus controller.  
If you select the RS-232 interface and then set the GPIB address to the  
talk only address (31), the multimeter will send readings over the  
RS-232 interface when in the local mode.  
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To Set the GPIB Address  
To Set the GPIB Address  
Each device on the GPIB (IEEE-488) interface must have a unique  
address. You can set the multimeters address to any value between  
0 and 31. The address is set to 22” when the multimeter is shipped from  
the factory. The address is displayed on the front panel when you turn  
on the multimeter. See also GPIB Address,” on page 91.  
On/Off  
Shift  
<
1 Tu r n on t h e fr on t -p a n el m en u .  
A: MEAS MENU  
<
<
2 Move a cr oss t o t h e I/O MENU ch oice on th is level.  
4
E: I/O MENU  
3 Move d ow n a level to t h e HP -IB ADDR com m a n d.  
1: HP-IB ADDR  
4
Move d ow n t o t h e pa r a m et er ” level t o set t h e a d d r ess.  
Use the left/right and down/up arrow keys to change the address.  
22  
ADDR  
Auto/Man  
ENTER  
5 Sa ve t h e ch a n ge a n d t u r n off t h e m en u .  
The address is stored in non-volatile memory, and does not change when  
power has been off or after a remote interface reset.  
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To Select the Remote Interface  
To Select the Remote Interface  
The multimeter is shipped with both an GPIB (IEEE-488) interface  
and an RS-232 interface. Only one interface can be enabled at a time.  
The GPIB interface is selected when the multimeter is shipped from  
the factory. See also Remote Interface Selection,” on page 92.  
On/Off  
Shift  
<
1 Tu r n on t h e fr on t -p a n el m en u .  
A: MEAS MENU  
<
<
2 Move a cr oss t o t h e I/O MENU ch oice on th is level.  
E: I/O MENU  
>
3 Move d ow n a level a n d t h en a cr oss t o t h e INTERF ACE com m a n d.  
2: INTERFACE  
4
Move d ow n t o t h e pa r a m et er ” level t o select t h e in t er fa ce.  
Use the left/right arrow keys to see the interface choices. Choose from  
the following: HP-IB / 488 or RS-232.  
HP-IB / 488  
Auto/Man  
ENTER  
5 Sa ve t h e ch a n ge a n d t u r n off t h e m en u .  
The interface selection is stored in non-volatile memory, and does not  
change when power has been off or after a remote interface reset.  
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To Set the Baud Rate  
To Set the Baud Rate  
You can select one of six baud rates for RS-232 operation. The rate is set  
to 9600 baud when the multimeter is shipped from the factory. See also  
Baud Rate Selection,” on page 93.  
On/Off  
Shift  
<
1 Tu r n on t h e fr on t -p a n el m en u .  
A: MEAS MENU  
<
<
2 Move a cr oss t o t h e I/O MENU ch oice on th is level.  
E: I/O MENU  
4
>
>
3 Move d ow n a level a n d t h en a cr oss t o t h e BAUD RATE com m a n d .  
3: BAUD RATE  
4
Move d ow n t o t h e pa r a m et er ” level t o select t h e ba u d r a t e.  
Use the left/right arrow keys to see the baud rate choices. Choose from  
one of the following: 300, 600, 1200, 2400, 4800, or 9600 baud.  
9600 BAUD  
Auto/Man  
ENTER  
5 Sa ve t h e ch a n ge a n d exit th e m en u .  
The baud rate selection is stored in non-volatile memory, and does not  
change when power has been off or after a remote interface reset.  
163  
Chapter 4 Remote Interface Reference  
To Set the Parity  
To Set the Parity  
You can select the parity for RS-232 operation. The multimeter is  
configured for even parity with 7 data bits when shipped from the  
factory. See also Parity Selection,” on page 93.  
On/Off  
Shift  
<
1 Tu r n on t h e fr on t -p a n el m en u .  
A: MEAS MENU  
<
<
2 Move a cr oss t o t h e I/O MENU ch oice on th is level.  
E: I/O MENU  
<
<
3 Move d ow n a level a n d t h en a cr oss t o t h e P ARITY com m a n d .  
4: PARITY  
4
Move d ow n to th e pa r a m eter ” level to select th e p a r ity.  
Use the left/right arrow keys to see the parity choices. Choose from one of  
the following: None (8 data bits), E ven (7 data bits), or Odd (7 data bits).  
When you set parity, you are indirectly setting the number of data bits.  
EVEN: 7 BITS  
Auto/Man  
ENTER  
5 Sa ve t h e ch a n ge a n d t u r n off t h e m en u .  
The parity selection is stored in non-volatile memory, and does not  
change when power has been off or after a remote interface reset.  
164  
Chapter 4 Remote Interface Reference  
To Select the Programming Language  
To Select the Programming Language  
You can select one of three languages to program the multimeter  
from the selected remote interface. The language is SCPI when  
the multimeter is shipped from the factory. See also Programming  
Language Selection,” on page 94.  
On/Off  
Shift  
<
1 Tu r n on t h e fr on t -p a n el m en u .  
A: MEAS MENU  
<
<
2 Move a cr oss t o t h e I/O MENU ch oice on th is level.  
E: I/O MENU  
4
<
3 Move d ow n a level a n d t h en a cr oss t o t h e LANGUAGE com m a n d .  
5: LANGUAGE  
4
Move d ow n t o t h e pa r a m et er ” level t o select t h e la n gu a ge.  
Choose from one of the following: SCP I, Agilent 3478A, or Fluke 8840A.  
SCPI  
Auto/Man  
ENTER  
5 Sa ve t h e ch a n ge a n d t u r n off t h e m en u .  
The language selection is stored in non-volatile memory, and does not  
change when power has been off or after a remote interface reset.  
165  
Chapter 4 Remote Interface Reference  
Alternate Programming Language Compatibility  
Alternate Programming Language Compatibility  
You can configure the Agilent 34401A to accept and execute the  
commands of either the Agilent 3478A multimeter or the Fluke  
8840A/8842A multimeter. Remote operation will only allow you to  
access the functionality of the multimeter language selected. You can  
take advantage of the full functionality of the 34401A only through the  
SCPI programming language. For more information on selecting the  
alternate languages from the front panel menu, see To Select the  
Programming Language,” on the previous page. From the remote  
interface, use the following commands to select the alternate languages:  
L1  
L2  
L3  
select SCPI language  
select Agilent 3478A language  
select Fluke 8840A language  
Virtually all of the commands available for the other two multimeters  
are implemented in the 34401A, with the exception of the self-test and  
calibration commands. You must always calibrate the 34401A using the  
SCPI language setting. The calibration commands from the other two  
multimeters will not be executed.  
Be aware that measurement timing may be different in the alternate  
language compatibility modes.  
Agilen t 3478A La n gu a ge Sett in g  
All Agilent 3478A commands are accepted and executed by the 34401A  
with equivalent operations, with the exception of the commands shown  
below. Refer to your Agilent 3478A Operating Manual for further  
remote interface programming information.  
3478A Command  
Description  
Agilent 34401A Action  
C
Perform a calibration.  
Perform a self-test and reset.  
Command is accepted but is ignored.  
Self-test is not executed.  
Device Clear  
166  
Chapter 4 Remote Interface Reference  
Alternate Programming Language Compatibility  
F lu k e 8840A/8842A La n gu a ge Sett in g  
All Fluke 8840A or 8842A commands are accepted and executed by  
the Agilent 34401A with equivalent operations, with the exception of  
the commands shown below. Refer to your Fluke 8840A or 8842A  
Instruction Manual for further remote interface programming information.  
Fluke 8840A  
Command  
Description  
Agilent 34401A Action  
GET calibration input prompt.  
GET calibration status.  
Return identification string.  
Generates Error 51 in 8840A/8842A.  
Returns “1000”.  
Returns “HEWLETT-PACKARD,  
34401A,0,X-X-X”  
G2  
G4  
G8  
PUT variable calibration value.  
PUT user-defined message.  
Perform self-test.  
Generates Error 51 in 8840A/8842A.  
Generates Error 51 in 8840A/8842A.  
Self-test is not executed and no  
errors are recorded in the status byte.  
Generates Error 51 in 8840A/8842A.  
Generates Error 51 in 8840A/8842A.  
Generates Error 51 in 8840A/8842A.  
Generates Error 51 in 8840A/8842A.  
P2  
P3  
Z0  
Store input as calibration value.  
Begin A/D calibration.  
Begin high-frequency AC calibration.  
Enter ERASE mode.  
C0  
C1  
C2  
C3  
4
167  
Chapter 4 Remote Interface Reference  
SCPI Compliance Information  
SCPI Compliance Information  
The following commands are device-specific to the Agilent 34401A. They  
are not included in the 1991.0 version of the SCPI standard. However,  
these commands are designed with the SCPI format in mind and they  
follow all of the syntax rules of the standard.  
Many of the required SCPI commands are accepted by the multimeter  
but are not described in this manual for simplicity or clarity. Most of  
these non-documented commands duplicate the functionality of a  
command already described in this chapter.  
CALCulate  
MEASure  
:AVERage:MINimum?  
:CONTinuity?  
:AVERage:MAXimum?  
:DIODe?  
:AVERage:AVERage?  
:AVERage:COUNt?  
SAMPle  
:COUNt {<value>|MINimum|MAXimum}  
:COUNt? [MINimum|MAXimum]  
:DB:REFerence {<value>|MINimum|MAXimum}  
:DB:REFerence? [MINimum|MAXimum]  
:DBM:REFerence {<value>|MINimum|MAXimum}  
:DBM:REFerence? [MINimum|MAXimum]  
:FUNCtion {NULL|DB|DBM|AVERage|LIMit}  
:FUNCtion?  
:LIMit:LOWer {<value>|MINimum|MAXimum}  
:LIMit:LOWer? [MINimum|MAXimum]  
:LIMit:UPPer {<value>|MINimum|MAXimum}  
:LIMit:UPPer? [MINimum|MAXimum]  
:NULL:OFFSet {<value>|MINimum|MAXimum}  
:NULL:OFFSet? [MINimum|MAXimum]  
[SENSe:]  
FUNCtion "CONTinuity"  
FUNCtion "DIODe"  
FREQuency:VOLTage:RANGe {<range>|MINimum|MAXimum}  
FREQuency:VOLTage:RANGe? [MINimum|MAXimum]  
FREQuency:VOLTage:RANGe:AUTO {OFF|ON}  
FREQuency:VOLTage:RANGe:AUTO?  
PERiod:VOLTage:RANGe {<range>|MINimum|MAXimum}  
PERiod:VOLTage:RANGe? [MINimum|MAXimum]  
PERiod:VOLTage:RANGe:AUTO {OFF|ON}  
PERiod:VOLTage:RANGe:AUTO?  
CALibration  
:COUNt?  
ZERO:AUTO?  
:SECure:CODE <new code>  
:SECure:STATe {OFF|ON},<code>  
:SECure:STATe?  
:STRing <quoted string>  
:STRing?  
SYSTem  
:LOCal  
:REMote  
:RWLock  
CONFigure  
:CONTinuity  
:DIODe  
INPut  
:IMPedance:AUTO {OFF|ON}  
:IMPedance:AUTO?  
168  
Chapter 4 Remote Interface Reference  
IEEE-488 Compliance Information  
IEEE-488 Compliance Information  
Dedicated Hardware Lines  
Addressed Commands  
ATN  
IFC  
REN  
SRQ  
Attention  
DCL  
EOI  
Device Clear  
Interface Clear  
Remote Enable  
Service Request Interrupt  
End or Identify Message Terminator  
Group Execute Trigger  
Go to Local  
GET  
GTL  
LLO  
SDC  
SPD  
SPE  
Local Lock-Out  
Selected Device Clear  
Serial Poll Disable  
Serial Poll Enable  
IEEE-488.2 Common Commands  
*RST  
*SRE <enable value>  
*SRE?  
4
*CLS  
*ESE <enable value>  
*ESE?  
*STB?  
*ESR?  
*TRG  
*IDN?  
*TST?  
*OPC  
*OPC?  
*PSC {0|1}  
*PSC?  
169  
170  
5
5
Error  
Messages  
Error Messages  
Errors are retrieved in first-in-first-out (FIFO) order. The first  
error returned is the first error that was stored. When you have  
read all errors from the queue, the ERROR annunciator turns off.  
The multimeter beeps once each time an error is generated.  
If more than 20 errors have occurred, the last error stored in the  
queue (the most recent error) is replaced with -350, Too many errors.  
No additional errors are stored until you remove errors from the  
queue. If no errors have occurred when you read the error queue,  
the multimeter responds with +0, No error.  
The error queue is cleared when power has been off or after a *CLS  
(clear status) command has been executed. The *RST(reset)  
command does not clear the error queue.  
Front-Panel Operation:  
3: ERROR (SYS MENU)  
If the ERROR annunciator is on, press Shift  
>
(Recall Menu) to  
read the errors stored in the queue. The errors are listed  
horizontally on the parameter” level. All errors are cleared when  
you go to the parameter” level and then turn off the menu.  
ERR 1: -113  
Error code  
First error in queue  
Remote Interface Operation:  
SYSTem:ERRor?  
Reads one error from the error queue  
Errors have the following format (the error string may contain  
up to 80 characters):  
-113,"Undefined header"  
172  
Chapter 5 Error Messages  
Execution Errors  
Execution Errors  
-101  
-102  
-103  
In va lid ch a r a ct er  
An invalid character was found in the command string. You may have  
inserted a character such as #, $, or % in the command header or within  
a parameter. Example: CONF:VOLT#DC  
Syn ta x er r or  
Invalid syntax was found in the command string. You may have  
inserted a blank space before or after a colon in the command header,  
or before a comma. Example: SAMP:COUN ,1  
In va lid sep a r a t or  
An invalid separator was found in the command string. You may have  
used a comma instead of a colon, semicolon, or blank space – or you may  
have used a blank space instead of a comma. Example: TRIG:COUN,1  
or CONF:FREQ 1000 0.1  
-104  
Da ta type er r or  
The wrong parameter type was found in the command string. You may  
have specified a number where a string was expected, or vice versa.  
Example: DISP:TEXT 5.0  
5
-105  
-108  
GET n ot a llow ed  
A Group Execute Trigger (GET) is not allowed within a command string.  
P a r a m et er n ot a llow ed  
More parameters were received than expected for the command.  
You may have entered an extra parameter, or you added a parameter  
to a command that does not accept a parameter. Example: READ? 10  
-109  
Missin g p a r a m et er  
Fewer parameters were received than expected for the command.  
You omitted one or more parameters that are required for this  
command. Example: SAMP:COUN  
173  
Chapter 5 Error Messages  
Execution Errors  
-112  
-113  
P r ogr a m m n em on ic t oo lon g  
A command header was received which contained more than the  
maximum 12 characters allowed. Example: CONFIGURATION:VOLT:DC  
Un d efin ed h ea d er  
A command was received that is not valid for this multimeter. You may  
have misspelled the command or it may not be a valid command. If you  
are using the short form of the command, remember that it may contain  
up to four letters. Example: TRIGG:COUN 3  
-121  
-123  
-124  
-131  
-138  
-148  
In va lid ch a r a ct er in n u m ber  
An invalid character was found in the number specified for a parameter  
value. Example: STAT:QUES:ENAB #B01010102  
Nu m er ic over flow  
A numeric parameter was found whose exponent was larger than 32,000.  
Example: TRIG:COUN 1E34000  
Too m a n y d igits  
A numeric parameter was found whose mantissa contained more than  
255 digits, excluding leading zeros.  
In va lid su ffix  
A suffix was incorrectly specified for a numeric parameter. You may  
have misspelled the suffix. Example: TRIG:DEL 0.5 SECS  
Su ffix n ot a llow ed  
A suffix was received following a numeric parameter which does not  
accept a suffix. Example: SAMP:COUN 1 SEC (SEC is not a valid suffix).  
Ch a r a cter da ta n ot a llow ed  
A discrete parameter was received but a character string or a numeric  
parameter was expected. Check the list of parameters to verify that you  
have used a valid parameter type. Example: DISP:TEXT ON  
174  
Chapter 5 Error Messages  
Execution Errors  
-151  
-158  
In va lid st r in g d a t a  
An invalid character string was received. Check to see if you have  
enclosed the character string in single or double quotes and that the  
string contains valid ASCII characters. Example: DISP:TEXT ’ON  
(the ending quote is missing).  
Str in g d a ta n ot a llow ed  
A character string was received but is not allowed for the command.  
Check the list of parameters to verify that you have used a valid  
parameter type. Example: CALC:STAT ’ON’  
-160 to -168  
-170 to -178  
-211  
Block da ta er r or s  
The multimeter does not accept block data.  
E xp r ession er r or s  
The multimeter does not accept mathematical expressions.  
Tr igger ign or ed  
A Group Execute Trigger (GET) or *TRG was received but the trigger  
was ignored. Make sure the multimeter is in the wait-for-trigger” state  
before issuing a trigger, and make sure the correct trigger source is selected.  
-213  
-214  
In it ign or ed  
An INITiatecommand was received but could not be executed because  
a measurement was already in progress. Send a device clear to halt a  
measurement in progress and place the multimeter in the idle” state.  
5
Tr igger d ea d lock  
A trigger deadlock occurs when the trigger source is BUS and a READ?  
command is received.  
175  
Chapter 5 Error Messages  
Execution Errors  
-221  
Sett in gs con flict  
This error can be generated in one of the following situations:  
You sent a CONFigure or MEASurecommand with autorange enabled  
and with a fixed resolution. Example: CONF:VOLT:DC DEF,0.1  
You turned math on (CALC:STAT ON) and then changed to a math  
operation that was not valid with the present measurement function.  
For example, dB measurements are not allowed with 2-wire ohms.  
The math state is turned off as a result of this condition.  
-222  
-223  
Da ta ou t of r a n ge  
A numeric parameter value is outside the valid range for the command.  
Example: TRIG:COUN -3  
Too m u ch d a t a  
A character string was received but could not be executed because the  
string length was more than 12 characters. This error can be generated  
by the CALibration:STRingand DISPlay:TEXTcommands.  
-224  
Illega l p a r a m et er va lu e  
A discrete parameter was received which was not a valid choice for  
the command. You may have used an invalid parameter choice.  
Example: CALC:FUNC SCALE (SCALE is not a valid choice).  
-230  
-330  
Da ta st a le  
A FETCh?command was received but internal reading memory was  
empty. The reading retrieved may be invalid.  
Self-t est fa iled  
The multimeters complete self-test failed from the remote interface  
(*TST?command). In addition to this error, more specific self-test errors  
are also reported. See also Self-Test Errors,” starting on page 179.  
176  
Chapter 5 Error Messages  
Execution Errors  
-350  
-410  
-420  
Too m a n y er r or s  
The error queue is full because more than 20 errors have occurred.  
No additional errors are stored until you remove errors from the queue.  
The error queue is cleared when power has been off, or after a *CLS  
(clear status) command has been executed.  
Qu er y INTERRUP TED  
A command was received which sends data to the output buffer, but the  
output buffer contained data from a previous command (the previous  
data is not overwritten). The output buffer is cleared when power has  
been off, or after a *RST(reset) command has been executed.  
Qu er y UNTERMINATE D  
The multimeter was addressed to talk (i.e., to send data over the  
interface) but a command has not been received which sends data to the  
output buffer. For example, you may have executed a CONFigure  
command (which does not generate data) and then attempted an ENTER  
statement to read data from the remote interface.  
-430  
-440  
Qu er y DEADLOCKED  
A command was received which generates too much data to fit in the  
output buffer and the input buffer is also full. Command execution  
continues but all data is lost.  
Qu er y UNTERMINATE D a ft er in d efin it e r esp on se  
The *IDN?command must be the last query command within a  
command string. Example: *IDN?;:SYST:VERS?  
5
177  
Chapter 5 Error Messages  
Execution Errors  
501  
502  
511  
512  
513  
514  
Isola t or UART fr a m in g er r or  
Isola tor UART over r u n er r or  
RS-232 fr a m in g er r or  
RS-232 over r u n er r or  
RS-232 p a r it y er r or  
Com m a n d a llow ed on ly w it h RS-232  
There are three commands which are only allowed with the RS-232  
interface: SYSTem:LOCal, SYSTem:REMote, and SYSTem:RWLock.  
521  
522  
531  
In p u t bu ffer over flow  
Ou tp u t bu ffer over flow  
In su fficien t m em or y  
There is not enough memory to store the requested number of readings  
in internal memory using the INITiatecommand. The product of the  
sample count (SAMPle:COUNt) and the trigger count (TRIGger:COUNt)  
must not exceed 512 readings.  
532  
540  
550  
Ca n n ot a ch ieve r equ est ed r esolu t ion  
The multimeter cannot achieve the requested measurement resolution.  
You may have specified an invalid resolution in the CONFigureor  
MEASurecommand.  
Ca n n ot u se over loa d a s m a t h r efer en ce  
The multimeter cannot store an overload reading (9.90000000E+37) as  
the math reference for null or dB measurements. The math state is  
turned off as a result of this condition.  
Com m a n d n ot allow ed in loca l  
The multimeter received a READ?or MEASure? command while in the  
local mode. During RS-232 operation, you should always execute the  
SYSTem:REMotecommand before sending other commands over the  
interface.  
178  
Chapter 5 Error Messages  
Self-Test Errors  
Self-Test Errors  
The following errors indicate failures that may occur during a self-test.  
Refer to the Service Guide for more information.  
601  
602  
603  
604  
605  
606  
607  
608  
609  
610  
611  
612  
613  
614  
615  
F r on t p a n el d oes n ot r esp on d  
RAM r ead /w r it e fa iled  
A/D syn c st u ck  
A/D slop e con ver gen ce fa iled  
Ca n n ot ca libr a t e r u n d ow n ga in  
Ru n d ow n ga in ou t of r a n ge  
Ru n d ow n t oo n oisy  
Ser ia l con figu r a t ion r ea d ba ck fa iled  
DC ga in x1 fa iled  
5
DC ga in x10 fa iled  
DC ga in x100 fa iled  
Oh m s 500 n A sou r ce fa iled  
Oh m s 5 u A sou r ce fa iled  
DC 1000V zer o fa iled  
Oh m s 10 u A sou r ce fa iled  
179  
Chapter 5 Error Messages  
Calibration Errors  
616  
617  
618  
619  
620  
621  
622  
623  
624  
625  
626  
DC cu r r en t sen se fa iled  
Oh m s 100 u A sou r ce fa iled  
DC h igh volt a ge a t ten u a t or fa iled  
Oh m s 1 m A sou r ce fa iled  
AC r m s zer o fa iled  
AC r m s fu ll sca le fa iled  
F r equ en cy cou n t er fa iled  
Ca n n ot ca libr a t e p r ech a r ge  
Un a ble t o sen se lin e fr equ en cy  
I/O p r ocessor d oes n ot r esp on d  
I/O p r ocessor fa iled self-t est  
Calibration Errors  
The following errors indicate failures that may occur during a  
calibration. Refer to the Service Guide for more information.  
701  
702  
Ca l secu r ity d isa bled by ju m p er  
The calibration security feature has been disabled with a jumper inside  
the multimeter. When applicable, this error will occur at power-on to  
warn you that the multimeter is unsecured.  
Ca l secu r ed  
The multimeter is secured against calibration.  
180  
Chapter 5 Error Messages  
Calibration Errors  
703  
In va lid secu r e cod e  
An invalid calibration security code was received when attempting to  
unsecure or secure the multimeter. You must use the same security code  
to unsecure the multimeter as was used to secure it, and vice versa. The  
security code may contain up to 12 alphanumeric characters. The first  
character must be a letter.  
704  
705  
Secu r e cod e too lon g  
A security code was received which contained more than 12 characters.  
Ca l a bor t ed  
A calibration in progress is aborted when you press any front-panel key,  
send a device clear, or change the local/remote state of the multimeter.  
706  
707  
708  
709  
Ca l va lu e ou t of r a n ge  
The specified calibration value (CALibration:VALue) is invalid for the  
present function and range.  
Ca l sign a l m ea su r em en t ou t of r a n ge  
The specified calibration value (CALibration:VALue) does not match  
the signal applied to the multimeter.  
Ca l sign a l fr equ en cy ou t of r a n ge  
The input signal frequency for an ac calibration does not match the  
required input frequency for calibration.  
5
No ca l for th is fu n ction or r a n ge  
You cannot perform calibrations for ac current, period, continuity, diode,  
ratio, or on the 100 Mrange.  
710  
720  
721  
722  
723  
724  
F u ll scale cor r ection ou t of r a n ge  
Ca l DCV offset ou t of r a n ge  
Ca l DCI offset ou t of r a n ge  
Ca l RES offset ou t of r a n ge  
Ca l F RES offset ou t of r a n ge  
Exten d ed r esista n ce self ca l fa iled  
181  
Chapter 5 Error Messages  
Calibration Errors  
725  
730  
731  
732  
733  
734  
735  
736  
740  
741  
742  
743  
744  
745  
746  
747  
748  
500V DC cor r ection ou t of r a n ge  
P r ech a r ge DAC con ver gen ce fa iled  
A/D tu r n over cor r ection ou t of r a n ge  
AC fla tn ess DAC con ver gen ce fa iled  
AC low fr equ en cy con ver gen ce fa iled  
AC low fr equ en cy cor r ect ion ou t of r a n ge  
AC r m s con ver t er n oise cor r ect ion ou t of r a n ge  
AC r m s 100t h sca le lin ea r it y cor r ection ou t of r a n ge  
Ca l ch eck su m fa iled, secu r e st a t e  
Ca l ch eck su m fa iled, st r in g d a t a  
Ca l ch eck su m fa iled, DCV cor r ection s  
Ca l ch eck su m fa iled, DCI cor r ection s  
Ca l ch eck su m fa iled, RE S cor r ect ion s  
Ca l ch eck su m fa iled, F RE S cor r ection s  
Ca l ch eck su m fa iled, AC cor r ect ion s  
Ca l ch eck su m fa iled, GP IB a d d r ess  
Ca l ch eck su m fa iled, in t er n a l d a t a  
182  
6
6
Application  
Programs  
Application Programs  
This chapter contains several remote interface application programs  
to help you develop programs for your measurement application.  
Chapter 4, Remote Interface Reference,” starting on page 103, lists the  
syntax for the SCPI (Standard Commands for Programmable  
Instruments) commands available to program the multimeter.  
The QuickBASIC example programs are written for the Agilent 82335A  
GPIB Interface Card and command library for IBM PC compatibles.  
The GPIB (IEEE-488) address is set to 22” when the multimeter is  
shipped from the factory. The examples in this chapter assume an GPIB  
address of 22. When sending a remote interface command, you append  
this address to the GPIB interfaces select code (normally 7). Therefore,  
with an address of “22” and a select code of 7, the combination is 722.  
IBM is a U.S. registered trademark of International Business Machines Corporation.  
184  
Chapter 6 Application Programs  
Using MEASure? for a Single Measurement  
Using MEASure? for a Single Measurement  
The following example uses the MEASure?command to make a single  
ac current measurement. This is the easiest way to program the  
multimeter for measurements. However, MEASure?does not offer much  
flexibility. The example is shown in BASIC and QuickBASIC.  
GPIB Operation Using BASIC  
10 REAL Rdg  
20 ASSIGN @Dmm TO 722  
30 CLEAR 7  
! Clear GPIB and dmm  
40 OUTPUT @Dmm; "*RST" ! Reset dmm  
50 OUTPUT @Dmm; "*CLS" ! Clear dmm status registers  
60 OUTPUT @Dmm; "MEASURE:CURRENT:AC? 1A,0.001MA" ! Set to 1 amp ac range  
70 ENTER @Dmm; Rdg  
80 PRINT Rdg  
90 END  
GPIB Operation Using QuickBASIC  
REM $Include "QBSetup"  
DEV&=722  
INFO1$="*RST"  
LENGTH1%=LEN(INFO1$)  
INFO2$="*CLS"  
LENGTH2%=LEN(INFO2$)  
INFO3$="MEASURE:CURRENT:AC? 1A,0.001MA"  
LENGTH3%=LEN(INFO3$)  
6
Call IOCLEAR(DEV&)  
Call IOOUTPUTS(DEV&, INFO1$, LENGTH1%)  
Call IOOUTPUTS(DEV&, INFO2$, LENGTH2%)  
Call IOOUTPUTS(DEV&, INFO3$, LENGTH3%)  
Call IOENTER(DEV&,Rdg)  
Print Rdg  
END  
185  
Chapter 6 Application Programs  
Using CONFigure with a Math Operation  
Using CONFigure with a Math Operation  
The following example uses CONFigurewith the dBm math operation.  
The CONFigurecommand gives you a little more programming  
flexibility than the MEASure?command. This allows you to  
incrementally” change the multimeters configuration. The example is  
shown in BASIC and QuickBASIC (see next page).  
GPIB Operation Using BASIC  
10 DIM Rdgs(1:5)  
20 ASSIGN @Dmm TO 722  
30 CLEAR 7  
! Clear GPIB and dmm  
40 OUTPUT @Dmm; "*RST" ! Reset dmm  
50 OUTPUT @Dmm; "*CLS" ! Clear dmm status registers  
60 OUTPUT @Dmm; "CALC:DBM:REF 50"  
! 50 ohm reference resistance  
70 OUTPUT @Dmm; "CONF:VOLT:AC 1,0.001" ! Set dmm to 1 amp ac range  
80 OUTPUT @Dmm; "DET:BAND 200"  
90 OUTPUT @Dmm; "TRIG:COUN 5"  
100 OUTPUT @Dmm; "TRIG:SOUR IMM"  
110 OUTPUT @Dmm; "CALC:FUNC DBM"  
120 OUTPUT @Dmm; "CALC:STAT ON"  
130 OUTPUT @Dmm; "READ?"  
! Select 200 Hz (fast) ac filter  
! Dmm will accept 5 triggers  
! Trigger source is IMMediate  
! Select dBm function  
! Enable math  
! Take readings; send to output buffer  
140 ENTER @Dmm; Rdgs(*)  
150 PRINT USING "K,/"; Rdgs(*)  
160 END  
186  
Chapter 6 Application Programs  
Using CONFigure with a Math Operation  
GPIB Operation Using QuickBASIC  
REM $Include "QBSetup"  
DEV&=722  
INFO1$="*RST"  
LENGTH1%=LEN(INFO1$)  
INFO2$="*CLS"  
LENGTH2%=LEN(INFO2$)  
INFO3$="CALC:DBM:REF 50"  
LENGTH3%=LEN(INFO3$)  
INFO4$="CONF:VOLT:AC 1,0.001"  
LENGTH4%=LEN(INFO4$)  
INFO5$="DET:BAND 200"  
LENGTH5%=LEN(INFO5$)  
INFO6$="TRIG:COUN 5"  
LENGTH6%=LEN(INFO6$)  
INFO7$="TRIG:SOUR IMM"  
LENGTH7%=LEN(INFO7$)  
INFO8$="CALC:FUNC DBM"  
LENGTH8%=LEN(INFO8$)  
INFO9$="CALC:STAT ON"  
LENGTH9%=LEN(INFO9$)  
INFO10$="READ?"  
LENGTH10%=LEN(INFO10$)  
DIM A(1:5)  
Actual%=0  
Call IOCLEAR(DEV&)  
Call IOOUTPUTS(DEV&, INFO1$, LENGTH1%)  
Call IOOUTPUTS(DEV&, INFO2$, LENGTH2%)  
Call IOOUTPUTS(DEV&, INFO3$, LENGTH3%)  
Call IOOUTPUTS(DEV&, INFO4$, LENGTH4%)  
Call IOOUTPUTS(DEV&, INFO5$, LENGTH5%)  
Call IOOUTPUTS(DEV&, INFO6$, LENGTH6%)  
Call IOOUTPUTS(DEV&, INFO7$, LENGTH7%)  
Call IOOUTPUTS(DEV&, INFO8$, LENGTH8%)  
Call IOOUTPUTS(DEV&, INFO9$, LENGTH9%)  
Call IOOUTPUTS(DEV&, INFO10$, LENGTH10%)  
Call IOENTER(DEV&, Seg A(1),5,Actual%)  
For I=1 to 5  
6
Print A(I);  
Next I  
END  
187  
Chapter 6 Application Programs  
Using the Status Registers  
Using the Status Registers  
The following example shows how you can use the multimeters status  
registers to determine when a command sequence is completed. For  
more information, see The SCPI Status Model,” starting on page 134.  
The example is shown in BASIC and QuickBASIC (see page 190).  
GPIB Operation Using BASIC  
10 REAL Aver,Min_rdg,Max_rdg  
20 INTEGER Val,Hpib,Mask,Task  
30 ASSIGN @Dmm TO 722  
40 CLEAR 7  
! Clear GPIB and dmm  
50 OUTPUT @Dmm; "*RST"  
60 OUTPUT @Dmm; "*CLS"  
! Reset dmm  
! Clear dmm status registers  
70 OUTPUT @Dmm; "*ESE 1" ! Enable "operation complete" bit to set  
! "standard event" bit in status byte  
80 OUTPUT @Dmm; "*SRE 32" ! Enable "standard event" bit in status byte  
! to pull the IEEE-488 SRQ line  
90 OUTPUT @Dmm; "*OPC?"  
100 ENTER @Dmm; Val  
110 !  
! Assure synchronization  
120 ! Configure the multimeter to make measurements  
130 !  
140 OUTPUT @Dmm; "CONF:VOLT:DC 10" ! Set dmm to 10 volt dc range  
150 OUTPUT @Dmm; "VOLT:DC:NPLC 10" ! Set the integration time to 10 PLCs  
160 OUTPUT @Dmm; "TRIG:COUN 100"  
! Dmm will accept 100 triggers  
170 OUTPUT @Dmm; "CALC:FUNC AVER;STAT ON" ! Select min-max and enable math  
180 OUTPUT @Dmm; "INIT"  
190 OUTPUT @Dmm; "*OPC"  
! Place dmm in "wait-for-trigger" state  
! Set "operation complete" bit in standard event  
! registers when measurement is complete  
200 !  
210 Hpib=7  
220 ON INTR Hpib GOSUB Read_data  
230 Mask=2  
! Bit 1 is SRQ  
240 ENABLE INTR Hpib;Mask ! Enable SRQ to interrupt the program  
250 !  
260 ! Execute other tasks while waiting for data  
270 !  
Continued on next page >  
188  
Chapter 6 Application Programs  
Using the Status Registers  
GPIB Operation Using BASIC (continued)  
280 Task=1  
290 WHILE Task=1  
300  
310  
320  
330  
DISP "Taking Readings"  
WAIT .5  
DISP ""  
WAIT .5  
340 END WHILE  
350 DISP "AVE = ";Aver; "  
360 STOP  
MIN = ";Min_rdg; "  
MAX = ";Max_rdg  
370 !  
380 Read_data:  
!
390 OUTPUT @Dmm; "CALC:AVER:AVER?;MIN?;MAX?" ! Read the average, min, and max  
400 ENTER @Dmm; Aver, Min_rdg, Max_rdg  
410 OUTPUT @Dmm; "*CLS"  
420 Task=0  
! Clear dmm status registers  
430 RETURN  
440 END  
6
189  
Chapter 6 Application Programs  
Using the Status Registers  
GPIB Operation Using QuickBASIC  
REM $Include "QBSetup"  
ISC&=7  
DEV&=722  
INFO1$="*RST"  
LENGTH1%=LEN(INFO1$)  
INFO2$="*CLS"  
LENGTH2%=LEN(INFO2$)  
INFO3$="*ESE 1"  
LENGTH3%=LEN(INFO3$)  
INFO4$="*SRE 32"  
LENGTH4%=LEN(INFO4$)  
INFO5$="*OPC?"  
LENGTH5%=LEN(INFO5$)  
INFO6$="CONF:VOLT:DC 10"  
LENGTH6%=LEN(INFO6$)  
INFO7$="VOLT:DC:NPLC 10"  
LENGTH7%=LEN(INFO7$)  
INFO8$="TRIG:COUN 100"  
LENGTH8%=LEN(INFO8$)  
INFO9$="CALC:FUNC AVER;STAT ON"  
LENGTH9%=LEN(INFO9$)  
INFO10$="INIT"  
LENGTH10%=LEN(INFO10$)  
INFO11$="*OPC"  
LENGTH11%=LEN(INFO11$)  
INFO12$="CALC:AVER:AVER?;MIN?;MAX?"  
LENGTH12%=LEN(INFO12$)  
INFO13$="*CLS"  
LENGTH13%=LEN(INFO13$)  
DIM A(1:3)  
Actual%=0  
Reading=0  
Continued on next page >  
190  
Chapter 6 Application Programs  
Using the Status Registers  
GPIB Operation Using QuickBASIC (continued)  
Call IOCLEAR(DEV&)  
Call IOOUTPUTS(DEV&, INFO1$, LENGTH1%)  
Call IOOUTPUTS(DEV&, INFO2$, LENGTH2%)  
ON PEN GOSUB RESULTS  
PEN ON  
Call IOPEN(ISC&,0)  
Call IOOUTPUTS(DEV&, INFO3$, LENGTH3%)  
Call IOOUTPUTS(DEV&, INFO4$, LENGTH4%)  
Call IOOUTPUTS(DEV&, INFO5$, LENGTH5%)  
Call IOENTER(DEV&,Reading)  
Call IOOUTPUTS(DEV&, INFO6$, LENGTH6%)  
Call IOOUTPUTS(DEV&, INFO7$, LENGTH7%)  
Call IOOUTPUTS(DEV&, INFO8$, LENGTH8%)  
Call IOOUTPUTS(DEV&, INFO9$, LENGTH9%)  
BACK:GOTO BACK  
RESULTS:  
Call IOOUTPUTS(DEV&, INFO10$, LENGTH10%)  
Call IOOUTPUTS(DEV&, INFO11$, LENGTH11%)  
Call IOOUTPUTS(DEV&, INFO12$, LENGTH12%)  
Call IOENTERA(DEV&, Seg A(1),3,Actual%)  
For I=1 to 3  
Print A(I);  
Next I  
Call IOOUTPUTS(DEV&, INFO13$, LENGTH13%)  
END  
6
191  
Chapter 6 Application Programs  
RS-232 Operation Using QuickBASIC  
RS-232 Operation Using QuickBASIC  
The following example shows how to send command instructions and  
receive command responses over the RS-232 interface using QuickBASIC.  
RS-232 Operation Using QuickBASIC  
CLS  
LOCATE 1, 1  
DIM cmd$(100), resp$(1000)  
’ Set up serial port for 9600 baud, even parity, 7 bits;  
’ Ignore Request to Send and Carrier Detect; Send line feed,  
’ enable parity check, reserve 1000 bytes for input buffer  
OPEN "com1:9600,e,7,2,rs,cd,lf,pe" FOR RANDOM AS #1 LEN = 1000  
’ Put the multimeter into the remote operation mode  
PRINT #1, ":SYST:REM"  
’ Query the multimeter’s id string  
PRINT #1, "*IDN?"  
LINE INPUT #1, resp$  
PRINT "*IDN? returned: ", resp$  
’ Ask what revision of SCPI the multimeter conforms to  
PRINT #1, ":SYST:VERS?"  
LINE INPUT #1, resp$  
PRINT ":SYST:VERS? returned: ", resp$  
’ Send a message to the multimeter’s display, and generate a beep  
PRINT #1, ":SYST:BEEP;:DISP:TEXT ’34401A’"  
’ Configure the multimeter for dc voltage readings,  
’ 10 V range, 0.1 V resolution, 4 readings  
PRINT #1, ":CONF:VOLT:DC 10,0.1;:SAMP:COUN 4"  
’ Trigger the readings, and fetch the results  
PRINT #1, ":READ?"  
LINE INPUT #1, resp$  
PRINT ":READ? returned: ", resp$  
END  
192  
Chapter 6 Application Programs  
RS-232 Operation Using Turbo C  
RS-232 Operation Using Turbo C  
The following example shows how to program an AT personal computer  
for interrupt-driven COM port communications. SCPI commands can be  
sent to the Agilent 34401A and responses received for commands that  
query information. The following program is written in Turbo C and can  
be easily modified for use with Microsoft Quick C.  
RS-232 Operation Using Turbo C  
#include <bios.h>  
#include <stdio.h>  
#include <string.h>  
#include <dos.h>  
#include <conio.h>  
#define EVEN_7 (0x18 | 0x02 | 0x04)  
#define ODD_7 (0x08 | 0x02 | 0x04)  
#define NONE_8 (0x00 | 0x03 | 0x04)  
#define BAUD300 0x40  
/* Even parity, 7 data, 2 stop */  
/* Odd parity, 7 data, 2 stop */  
/* None parity, 8 data, 2 stop */  
#define BAUD600 0x60  
#define BAUD1200 0x80  
#define BAUD2400 0xA0  
#define BAUD4800 0xC0  
#define BAUD9600 0xE0  
/* 8250 UART Registers */  
#define COM 0x3F8 /* COM1 base port address */  
#define THR COM+0 /* LCR bit 7 = 0 */  
#define RDR COM+0 /* LCR bit 7 = 0 */  
#define IER COM+1 /* LCR bit 7 = 0 */  
#define IIR COM+2 /* The rest are don’t care for bit 7 */  
#define LCR COM+3  
6
#define MCR COM+4  
#define LSR COM+5  
#define MSR COM+6  
Continued on next page >  
Microsoft is a U.S. registered trademark of Microsoft Corporation.  
193  
Chapter 6 Application Programs  
RS-232 Operation Using Turbo C  
RS-232 Operation Using Turbo C (continued)  
#define IRQ4_int  
#define IRQ4_enab  
#define INT_controller 0x20  
#define End_of_interrupt 0x20  
0xC  
0xEF  
/* IRQ4 interrupt vector number */  
/* IRQ4 interrupt controller enable mask */  
/* 8259 Interrupt controller address */  
/* Non-specific end of interrupt command */  
void interrupt int_char_in(void);  
void send_ctlc(void);  
#define INT_BUF_size 9000  
char int_buf[INT_BUF_size], *int_buf_in = int_buf, *int_buf_out = int_buf;  
unsigned int int_buf_count = 0;  
unsigned char int_buf_ovfl = 0;  
int main(int argc, char *argv[])  
{
void interrupt (*oldvect)();  
char command[80], c;  
int i;  
oldvect = getvect(IRQ4_int);  
setvect(IRQ4_int,int_char_in);  
bioscom(0,BAUD9600 | EVEN_7,0);  
outportb(MCR,0x9);  
/* Save old interrupt vector */  
/* Set up new interrupt handler */  
/* Initialize settings for COM1 */  
/* Enable IRQ buffer, DTR = 1 */  
/* Enable UART data receive interrupt */  
outportb(IER,0x1);  
/* Enable IRQ4 in 8259 interrupt controller register */  
outportb(INT_controller+1,inportb(INT_controller+1) & IRQ4_enab);  
do {  
if(int_buf_ovfl) {  
printf("\nBuffer Overflow!!!\n\n");  
int_buf_in  
= int_buf_out = int_buf;  
int_buf_count = int_buf_ovfl = 0;  
}
Continued on next page >  
194  
Chapter 6 Application Programs  
RS-232 Operation Using Turbo C  
RS-232 Operation Using Turbo C (continued)  
printf("\nEnter command string:\n");  
gets(command); strcat(command,"\n");  
/* SCPI requires line feed */  
/* If ^Y then send ^C */  
if(command[0] == 0x19) send_ctlc();  
else if(command[0] != ’q’) {  
for(i=0; i<strlen(command); i++) {  
/* Wait for DSR and transmitter hold register empty */  
while(!(inportb(LSR) & inportb(MSR) & 0x20)) ;  
outportb(THR,command[i]);  
}
/* Send character */  
}
if(strpbrk(command,"?")) {  
/* If query then get response */  
c = 0;  
do {  
while(int_buf_count && !kbhit()) {  
putch(c = *int_buf_out++); int_buf_count--;  
if(int_buf_out >= int_buf + INT_BUF_size) int_buf_out = int_buf;  
}
if(kbhit()) {  
if(getch() == 0x19) send_ctlc(); /* if ^Y then send ^C */  
c = 0xa;  
}
/* Terminate loop */  
}
while(c != 0xa);  
/* End if */  
}
}
while(command[0] != ’q’);  
/* ’q’ to quit program */  
outportb(IER,inportb(IER) & 0xfe);  
outportb(MCR,0x1);  
/* Disable UART interrupt */  
/* Disable IRQ buffer, DTR = 1 */  
6
/* Disable IRQ4 in 8259 interrupt controller register */  
outportb(INT_controller+1,inportb(INT_controller+1) | ~IRQ4_enab);  
setvect(IRQ4_int,oldvect);  
/* Restore old interrupt vector */  
return(0);  
}
Continued on next page >  
195  
Chapter 6 Application Programs  
RS-232 Operation Using Turbo C  
RS-232 Operation Using Turbo C (continued)  
void interrupt int_char_in(void)  
{
enable();  
/* Enable hardware interrupts */  
/* Read byte from UART */  
if(int_buf_count < INT_BUF_size) {  
*int_buf_in++ = inportb(RDR);  
int_buf_count++;  
if(int_buf_in >= int_buf + INT_BUF_size) int_buf_in = int_buf;  
int_buf_ovfl = 0;  
}
else {  
inportb(RDR);  
/* Clear UART interrupt */  
int_buf_ovfl = 1;  
}
outportb(INT_controller,End_of_interrupt); /* Non-specific EOI */  
}
void send_ctlc(void)  
{
outportb(MCR,0x8);  
/* De-assert DTR */  
delay(10);  
while(!(inportb(LSR) & 0x20)) ;  
outportb(THR,0x3);  
/* Wait 10 mS for stray characters */  
/* Wait on transmitter register */  
/* Send ^C */  
while(!(inportb(LSR) & 0x40)) ;  
int_buf_in = int_buf_out = int_buf;  
int_buf_count = int_buf_ovfl = 0;  
delay(20);  
/* Wait for ^C to be sent */  
/* Clear int_char_in buffer */  
/* 20mS for 34401 to clean up */  
/* Assert DTR */  
outportb(MCR,0x9);  
}
196  
7
7
Measurement  
Tutorial  
Measurement Tutorial  
The Agilent 34401A is capable of making highly accurate  
measurements. In order to achieve the greatest accuracy, you must take  
the necessary steps to eliminate potential measurement errors. This  
chapter describes common errors found in measurements and gives  
suggestions to help you avoid these errors.  
Th er m a l E MF Er r or s  
Thermoelectric voltages are the most common source of error in  
low-level dc voltage measurements. Thermoelectric voltages are  
generated when you make circuit connections using dissimilar metals  
at different temperatures. Each metal-to-metal junction forms a  
thermocouple, which generates a voltage proportional to the junction  
temperature. You should take the necessary precautions to minimize  
thermocouple voltages and temperature variations in low-level voltage  
measurements. The best connections are formed using copper-to-copper  
crimped connections. The table below shows common thermoelectric  
voltages for connections between dissimilar metals.  
Copper-to-  
Approx. µV / °C  
Copper  
Gold  
Silver  
Brass  
<0.3  
0.5  
0.5  
3
Beryllium Copper  
Aluminum  
5
5
Kovar or Alloy 42  
Silicon  
Copper-Oxide  
Cadmium-Tin Solder  
Tin-Lead Solder  
40  
500  
1000  
0.2  
5
The Agilent 34401As input terminals are copper alloy.  
198  
Chapter 7 Measurement Tutorial  
Loading Errors (dc volts)  
Loa d in g Er r or s (d c volt s)  
Measurement loading errors occur when the resistance of the device-  
under-test (DUT) is an appreciable percentage of the multimeters own  
input resistance. The diagram below shows this error source.  
Rs  
V = ideal DUT voltage  
s
HI  
R = DUT source resistance  
s
R = multimeter input resistance  
i
Ideal  
Meter  
Vs  
Ri  
( 10 Mor >10 G)  
100 x Rs  
LO  
Error (%) =  
Rs + Ri  
To reduce the effects of loading errors, and to minimize noise pickup,  
you can set the multimeters input resistance to greater than 10 Gfor  
the 100 mVdc, 1 Vdc, and 10 Vdc ranges. The input resistance is  
maintained at 10 Mfor the 100 Vdc and 1000 Vdc ranges.  
Lea k a ge Cu r r en t Er r or s  
The multimeters input capacitance will charge up” due to input bias  
currents when the terminals are open-circuited (if the input resistance  
is 10 G). The multimeters measuring circuitry exhibits approximately  
30 pA of input bias current for ambient temperatures from 0°C to 30°C.  
Bias current will double (×2) for every 8°C change in ambient temperature  
above 30°C. This current generates small voltage offsets dependent upon  
the source resistance of the device-under-test. This effect becomes  
evident for a source resistance of greater than 100 k, or when the  
multimeters operating temperature is significantly greater than 30°C.  
R
s
i = multimeter bias current  
b
R = DUT source resistance  
s
HI  
C = multimeter input capacitance  
i
For DCV ranges:  
0.1V, 1V, 10V: C < 700 pF  
i
100V, 1000V: C < 50 pF  
i
Ideal  
Meter  
V
s
ib  
R
i
Ci  
7
For all ACV ranges: < 50 pF  
LO  
Error (v) i x R  
b
s
199  
Chapter 7 Measurement Tutorial  
Rejecting Power-Line Noise Voltages  
Reject in g P ower -Lin e Noise Volt a ges  
A desirable characteristic of integrating analog-to-digital (A/D) converters  
is their ability to reject spurious signals. Integrating techniques reject  
power-line related noise present with dc signals on the input. This is  
called normal mode rejection or NMR. Normal mode noise rejection is  
achieved when the multimeter measures the average of the input by  
integrating” it over a fixed period. If you set the integration time to a  
whole number of power line cycles (PLCs) of the spurious input, these  
errors (and their harmonics) will average out to approximately zero.  
The Agilent 34401A provides three A/D integration times to reject  
power-line frequency noise (and power-line frequency harmonics). When  
you apply power to the multimeter, it measures the power-line  
frequency (50 Hz or 60 Hz), and then determines the proper integration  
time. The table below shows the noise rejection achieved with various  
configurations. For better resolution and increased noise rejection,  
select a longer integration time.  
Integration Time  
Digits  
NPLCs  
NMR  
60 Hz (50 Hz)  
412 Fast  
412 Slow  
512 Fast  
512 Slow  
612 Fast  
612 Slow  
0.02  
1
0.2  
10  
10  
100  
400 µs  
16.7 ms (20 ms)  
3 ms (3 ms)  
167 ms (200 ms)  
167 ms (200 ms)  
1.67 sec (2 sec)  
(400 µs)  
60 dB  
60 dB  
60 dB  
60 dB  
200  
Chapter 7 Measurement Tutorial  
Common Mode Rejection (CMR)  
Com m on Mod e R ejection (CMR)  
Ideally, a multimeter is completely isolated from earth-referenced circuits.  
However, there is finite resistance between the multimeters input LO  
terminal and earth ground as shown below. This can cause errors when  
measuring low voltages which are floating relative to earth ground.  
HI  
V = float voltage  
f
R = DUT source resistance  
s
imbalance  
R = multimeter isolation  
i
Ideal  
Meter  
Vtest  
Rs  
resistance (LO-Earth)  
C = multimeter input  
i
LO  
capacitance:  
200 pF (LO-Earth)  
Vf  
Ci  
Ri >10 GΩ  
Vf x Rs  
Error ( v ) =  
Rs + Ri  
Noise Ca u sed b y Ma gn etic Loop s  
If you are making measurements near magnetic fields, you should take  
the necessary precautions to avoid inducing voltages in the measurement  
connections. You should be especially careful when working near  
conductors carrying large currents. Use twisted-pair connections to the  
multimeter to reduce the noise pickup loop area, or dress the test leads  
as close together as possible. Loose or vibrating test leads will also  
induce error voltages. Make sure your test leads are tied down securely  
when operating near magnetic fields. Whenever possible, use magnetic  
shielding materials or physical separation to reduce problem magnetic  
field sources.  
7
201  
Chapter 7 Measurement Tutorial  
Noise Caused by Ground Loops  
Noise Ca u sed b y Gr ou n d Loop s  
When measuring voltages in circuits where the multimeter and the  
device-under-test are both referenced to a common earth ground,  
a ground loop” is formed. As shown below, any voltage difference  
between the two ground reference points (Vground) causes a current to  
flow through the measurement leads. This causes errors, such as noise  
and offset voltage (usually power-line related), which are added to the  
measured voltage.  
The best way to eliminate ground loops is to maintain the multimeters  
isolation from earth; do not connect the input terminals to ground.  
If the multimeter must be earth-referenced, be sure to connect it,  
and the device-under-test, to the same common ground point. This will  
reduce or eliminate any voltage difference between the devices.  
Also make sure the multimeter and device-under-test are connected to  
the same electrical outlet whenever possible.  
RL  
HI  
Ideal  
Meter  
Vtest  
RL  
LO  
Ri >10 GΩ  
Vground  
RL = lead resistance  
Ri = multimeter isolation resistance  
Vground = voltage drop on ground bus  
202  
Chapter 7 Measurement Tutorial  
Resistance Measurements  
Resista n ce Mea su r em en ts  
The Agilent 34401A offers two methods for measuring resistance:  
2-wire and 4-wire ohms. For both methods, the test current flows from  
the input HI terminal and then through the resistor being measured. For  
2-wire ohms, the voltage drop across the resistor being measured is  
sensed internal to the multimeter. Therefore, test lead resistance is also  
measured. For 4-wire ohms, separate sense” connections are required.  
Since no current flows in the sense leads, the resistance in these leads  
does not give a measurement error.  
The errors mentioned earlier in this chapter for dc voltage measurements  
also apply to resistance measurements. Additional error sources unique  
to resistance measurements are discussed on the following pages.  
4-Wir e Oh m s Mea su r em en ts  
The 4-wire ohms method provides the most accurate way to measure  
small resistances. Test lead resistances and contact resistances are  
automatically reduced using this method. Four-wire ohms is often used  
in automated test applications where long cable lengths, numerous  
connections, or switches exist between the multimeter and the device-  
under-test. The recommended connections for 4-wire ohms  
measurements are shown below. See also To Measure Resistance,”  
on page 17.  
HI  
HI-Sense  
Vmeter  
Ideal  
Meter  
R =  
I
test  
I test  
LO-Sense  
7
LO  
203  
Chapter 7 Measurement Tutorial  
Removing Test Lead Resistance Errors  
Rem ovin g Test Lea d Resista n ce Er r or s  
To eliminate offset errors associated with the test lead resistance in  
2-wire ohms measurements, follow the steps below.  
1. Short the ends of the test leads together. The multimeter displays the  
test lead resistance.  
2. Press Null from the front panel. The multimeter displays 0”  
ohms with the leads shorted together.  
P ower Dissip a tion Effect s  
When measuring resistors designed for temperature measurements  
(or other resistive devices with large temperature coefficients), be aware  
that the multimeter will dissipate some power in the device-under-test.  
If power dissipation is a problem, you should select the multimeters  
next higher measurement range to reduce the errors to acceptable  
levels. The following table shows several examples.  
DUT  
Range  
Test Current  
Power at Full Scale  
100 Ω  
1 kΩ  
1 mA  
1 mA  
100 µW  
1 mW  
10 kΩ  
100 kΩ  
1 MΩ  
100 µA  
10 µA  
5 µA  
100 µW  
10 µW  
30 µW  
3 µW  
10 MΩ  
500 nA  
Sett lin g Tim e E ffects  
The 34401A has the ability to insert automatic measurement settling  
delays. These delays are adequate for resistance measurements with less  
than 200 pF of combined cable and device capacitance. This is particularly  
important if you are measuring resistances above 100 k. Settling due to  
RC time constant effects can be quite long. Some precision resistors and  
multi-function calibrators use large parallel capacitors (1000 pF to 0.1 µF)  
with high resistor values to filter out noise currents injected by their  
internal circuitry. Non-ideal capacitances in cables and other devices may  
have much longer settling times than expected just by RC time constants  
due to dielectric absorption (soak) effects. Errors will be measured when  
settling after the initial connection and after a range change.  
204  
Chapter 7 Measurement Tutorial  
Errors in High Resistance Measurements  
Er r or s in High Resist a n ce Mea su r em en t s  
When you are measuring large resistances, significant errors can occur  
due to insulation resistance and surface cleanliness. You should take  
the necessary precautions to maintain a clean” high-resistance system.  
Test leads and fixtures are susceptible to leakage due to moisture  
absorption in insulating materials and dirty” surface films. Nylon and  
PVC are relatively poor insulators (109 ohms) when compared to PTFE  
13  
Teflon insulators (10 ohms). Leakage from nylon or PVC insulators  
can easily contribute a 0.1% error when measuring a 1 Mresistance in  
humid conditions.  
DC Cu r r en t Mea su r em en t Er r or s  
When you connect the multimeter in series with a test circuit to  
measure current, a measurement error is introduced. The error is  
caused by the multimeters series burden voltage. A voltage is developed  
across the wiring resistance and current shunt resistance of the  
multimeter as shown below.  
Rs  
I
Ideal  
Meter  
Vb  
R
Vs  
LO  
V
s
= source voltage  
R
= DUT source resistance  
= multimeter burden voltage  
= multimeter current shunt  
s
V
b
R
100% x Vb  
Error ( % ) =  
7
Vs  
Teflon is a registered trademark of E.I. duPont deNemours and Co.  
205  
Chapter 7 Measurement Tutorial  
True RMS AC Measurements  
Tr u e R MS AC Mea su r em en ts  
True RMS responding multimeters, like the Agilent 34401A, measure  
the heating” potential of an applied voltage. Unlike an average  
responding” measurement, a true RMS measurement is used to  
determine the power dissipated in a resistor. The power is proportional  
to the square of the measured true RMS voltage, independent of  
waveshape. An average responding ac multimeter is calibrated to read  
the same as a true RMS meter for sinewave inputs only. For other  
waveform shapes, an average responding meter will exhibit substantial  
errors as shown below.  
The multimeters ac voltage and ac current functions measure the  
ac-coupled true RMS value. This is in contrast to the ac+dc true RMS  
value shown above. Only the heating value” of the ac components of the  
input waveform are measured (dc is rejected). For sinewaves, triangle  
waves, and square waves, the ac and ac+dc values are equal since these  
waveforms do not contain a dc offset. Non-symmetrical waveforms, such  
as pulse trains, contain dc voltages which are rejected by ac-coupled  
true RMS measurements.  
206  
Chapter 7 Measurement Tutorial  
Crest Factor Errors (non-sinusoidal inputs)  
An ac-coupled true RMS measurement is desirable in situations where  
you are measuring small ac signals in the presence of large dc offsets.  
For example, this situation is common when measuring ac ripple  
present on dc power supplies. There are situations, however, where you  
might want to know the ac+dc true RMS value. You can determine this  
value by combining results from dc and ac measurements as shown  
below. You should perform the dc measurement using at least 10 power  
line cycles of integration (6 digit mode) for best ac rejection.  
ac + dc =  
ac2 + dc2  
Cr est F a ct or Er r or s (n on -sin u soid a l in p u ts)  
A common misconception is that since an ac multimeter is true RMS,  
its sinewave accuracy specifications apply to all waveforms.” Actually,  
the shape of the input signal can dramatically affect measurement  
accuracy. A common way to describe signal waveshapes is crest factor.  
Crest factor is the ratio of the peak value to RMS value of a waveform.  
For a pulse train, for example, the crest factor is approximately equal to  
the square root of the inverse of the duty cycle as shown in the table on  
the previous page. In general, the greater the crest factor, the greater  
the energy contained in higher frequency harmonics. All multimeters  
exhibit measurement errors that are crest factor dependent. Crest factor  
errors for the Agilent 34401A are shown in the specifications in chapter  
8. Note that the crest factor errors do not apply for input signals below  
100 Hz when using the slow ac filter.  
7
207  
Chapter 7 Measurement Tutorial  
Crest Factor Errors (non-sinusoidal inputs)  
Crest Factor  
(continued)  
You can estimate the measurement error due to signal crest factor as  
shown below:  
Total Error = Error (sine) + Error (crest factor) + Error (bandwidth)  
Error (sine): error for sinewave as shown in chapter 8.  
Error (crest factor): crest factor additional error as shown in chapter 8.  
Error (bandwidth): estimated bandwidth error as shown below.  
C.F. = signal crest factor  
2
C.F. x F  
F = input fundamental frequency  
Bandwidth Error =  
BW = multimeter’s 3 dB bandwidth  
4 π x BW  
(1 MHz for the Agilent 34401A )  
Example  
Calculate the approximate measurement error for a pulse train input  
with a crest factor of 3 and a fundamental frequency of 20 kHz. For this  
example, assume the multimeters 90-day accuracy specifications:  
± (0.05% + 0.03%).  
Total Error = 0.08% + 0.15% + 1.4% = 1.6%  
208  
Chapter 7 Measurement Tutorial  
Loading Errors (ac volts)  
Loa d in g Er r or s (a c volts)  
In the ac voltage function, the input of the Agilent 34401A appears as a  
1 Mresistance in parallel with 100 pF of capacitance. The cabling that  
you use to connect signals to the multimeter will also add additional  
capacitance and loading. The table below shows the multimeters  
approximate input resistance at various frequencies.  
Input Frequency  
Input Resistance  
100 Hz  
1 kHz  
10 kHz  
100 kHz  
1 MΩ  
850 kΩ  
160 kΩ  
16 kΩ  
For low frequencies:  
100 x Rs  
Error (%) =  
Rs + 1 MΩ  
Additional error for high frequencies:  
1
!
1
2
2
2
3
Error (%) = 100 x  
1  
"
"
"
#
1 + ( 2 π x F x Rs x Cin )2  
Rs = source resistance  
F = input frequency  
Cin = input capacitance (100 pF) plus cable capacitance  
7
209  
Chapter 7 Measurement Tutorial  
Measurements Below Full Scale  
Mea su r em en ts Below F u ll Sca le  
You can make the most accurate ac measurements when the multimeter  
is at full scale of the selected range. Autoranging occurs at 10% and  
120% of full scale. This enables you to measure some inputs at full scale  
on one range and 10% of full scale on the next higher range. The accuracy  
will be significantly different for these two cases. For highest accuracy,  
you should use manual range to get to the lowest range possible for the  
measurement.  
High -Volta ge Self-Hea t in g Er r or s  
If you apply more than 300 Vrms, self-heating will occur in the  
multimeters internal signal-conditioning components. These errors are  
included in the multimeters specifications. Temperature changes inside  
the multimeter due to self-heating may cause additional error on other  
ac voltage ranges. The additional error will be less than 0.02% and will  
dissipate in a few minutes.  
Tem p er a tu r e Coefficien t a n d Over loa d E r r or s  
The Agilent 34401A uses an ac measurement technique that measures  
and removes internal offset voltages when you select a different function  
or range. If you leave the multimeter in the same range for an extended  
period of time, and the ambient temperature changes significantly (or if  
the multimeter is not fully warmed up), the internal offsets may change.  
This temperature coefficient is typically 0.002% of range per °C and is  
automatically removed when you change functions or ranges.  
When manual ranging to a new range in an overload condition, the  
internal offset measurement may be degraded for the selected range.  
Typically, an additional 0.01% of range error may be introduced.  
This additional error is automatically removed when you remove the  
overload condition and then change functions or ranges.  
210  
Chapter 7 Measurement Tutorial  
Low-Level Measurement Errors  
Low -Level Mea su r em en t Er r or s  
When measuring ac voltages less than 100 mV, be aware that these  
measurements are especially susceptible to errors introduced by  
extraneous noise sources. An exposed test lead will act as an antenna  
and a properly functioning multimeter will measure the signals  
received. The entire measurement path, including the power line, act as  
a loop antenna. Circulating currents in the loop will create error  
voltages across any impedances in series with the multimeters input.  
For this reason, you should apply low-level ac voltages to the  
multimeter through shielded cables. You should connect the shield to  
the input LO terminal.  
Make sure the multimeter and the ac source are connected to the same  
electrical outlet whenever possible. You should also minimize the area  
of any ground loops that cannot be avoided. A high-impedance source is  
more susceptible to noise pickup than a low-impedance source. You can  
reduce the high-frequency impedance of a source by placing a capacitor  
in parallel with the multimeters input terminals. You may have to  
experiment to determine the correct capacitor value for your application.  
Most extraneous noise is not correlated with the input signal. You can  
determine the error as shown below.  
2
Voltage Measured =  
Vin + Noise 2  
Correlated noise, while rare, is especially detrimental. Correlated noise  
will always add directly to the input signal. Measuring a low-level  
signal with the same frequency as the local power line is a common  
situation that is prone to this error.  
7
211  
Chapter 7 Measurement Tutorial  
Common Mode Errors  
Com m on Mod e Er r or s  
Errors are generated when the multimeters input LO terminal is driven  
with an ac voltage relative to earth. The most common situation where  
unnecessary common mode voltages are created is when the output of  
an ac calibrator is connected to the multimeter backwards.” Ideally,  
a multimeter reads the same regardless of how the source is connected.  
Both source and multimeter effects can degrade this ideal situation.  
Because of the capacitance between the input LO terminal and earth  
(approximately 200 pF for the Agilent 34401A), the source will  
experience different loading depending on how the input is applied. The  
magnitude of the error is dependent upon the sources response to this  
loading. The multimeters measurement circuitry, while extensively  
shielded, responds differently in the backward input case due to slight  
differences in stray capacitance to earth. The multimeters errors are  
greatest for high- voltage, high-frequency inputs. Typically, the  
multimeter will exhibit about 0.06% additional error for a 100 V, 100  
kHz reverse input. You can use the grounding techniques described for  
dc common mode problems to minimize ac common mode voltages (see  
page 201).  
AC Cu r r en t Mea su r em en t Er r or s  
Burden voltage errors, which apply to dc current, also apply to ac  
current measurements. However, the burden voltage for ac current is  
larger due to the multimeters series inductance and your measurement  
connections. The burden voltage increases as the input frequency  
increases. Some circuits may oscillate when performing current  
measurements due to the multimeters series inductance and your  
measurement connections.  
212  
Chapter 7 Measurement Tutorial  
Frequency and Period Measurement Errors  
F r eq u en cy a n d P er iod Mea su r em en t Er r or s  
The multimeter uses a reciprocal counting technique to measure  
frequency and period. This method generates constant measurement  
resolution for any input frequency. The multimeters ac voltage  
measurement section performs input signal conditioning. All frequency  
counters are susceptible to errors when measuring low-voltage,  
low-frequency signals. The effects of both internal noise and external  
noise pickup are critical when measuring slow” signals. The error is  
inversely proportional to frequency. Measurement errors will also occur  
if you attempt to measure the frequency (or period) of an input following  
a dc offset voltage change. You must allow the multimeters input dc  
blocking capacitor to fully settle before making frequency measurements.  
Ma k in g High -Sp eed DC a n d Resist a n ce Mea su r em en t s  
The multimeter incorporates an automatic zero measurement procedure  
(autozero) to eliminate internal thermal EMF and bias current errors.  
Each measurement actually consists of a measurement of the input  
terminals followed by a measurement of the internal offset voltage.  
The internal offset voltage error is subtracted from the input for improved  
accuracy. This compensates for offset voltage changes due to temperature.  
For maximum reading speed, turn autozero off. This will more than double  
your reading speeds for dc voltage, resistance, and dc current functions.  
Autozero does not apply to other measurement functions.  
7
213  
Chapter 7 Measurement Tutorial  
Making High-Speed AC Measurements  
Ma k in g High -Sp eed AC Mea su r em en t s  
The multimeters ac voltage and ac current functions implement three  
different low-frequency filters. These filters allow you to trade-off low  
frequency accuracy for faster reading speed. The fast filter settles in  
0.1 seconds, and is useful for frequencies above 200 Hz. The medium  
filter settles in 1 second, and is useful for measurements above 20 Hz.  
The slow filter settles in 7 seconds, and is useful for frequencies above 3 Hz.  
With a few precautions, you can perform ac measurements at speeds up  
to 50 readings per second. Use manual ranging to eliminate autoranging  
delays. By setting the preprogrammed settling (trigger) delays to 0,  
each filter will allow up to 50 readings per second. However, the  
measurement might not be very accurate since the filter is not fully  
settled. In applications where sample-to-sample levels vary widely,  
the medium filter will settle at 1 reading per second, and the fast filter  
will settle at 10 readings per second.  
If the sample-to-sample levels are similar, little settling time is required  
for each new reading. Under this specialized condition, the medium  
filter will provide reduced accuracy results at 5 readings per second,  
and the fast filter will provide reduced accuracy results at 50 readings  
per second. Additional settling time may be required when the dc level  
varies from sample to sample. The multimeters dc blocking circuitry  
has a settling time constant of 0.2 seconds. This settling time only  
affects measurement accuracy when dc offset levels vary from sample  
to sample. If maximum measurement speed is desired in a scanning  
system, you may want to add an external dc blocking circuit to those  
channels with significant dc voltages present. This circuit can be as  
simple as a resistor and a capacitor.  
214  
8
Specifications  
8
Chapter 8 Specifications  
DC Characteristics  
DC Characteristics  
Accuracy Specifications ± ( % of reading + % of range ) [ 1 ]  
Temperature  
Coefficient /°C  
0°C – 18°C  
Test Current or  
Burden Voltage  
90 Day  
23°C ± 5°C  
1 Year  
23°C ± 5°C  
24 Hour [ 2 ]  
23°C ± 1°C  
Function  
Range [ 3 ]  
28°C – 55°C  
DC Voltage  
100.0000 mV  
1.000000 V  
10.00000 V  
100.0000 V  
1000.000 V  
0.0030 + 0.0030  
0.0020 + 0.0006  
0.0015 + 0.0004  
0.0020 + 0.0006  
0.0020 + 0.0006  
0.0040 + 0.0035  
0.0030 + 0.0007  
0.0020 + 0.0005  
0.0035 + 0.0006  
0.0035 + 0.0010  
0.0050 + 0.0035  
0.0040 + 0.0007  
0.0035 + 0.0005  
0.0045 + 0.0006  
0.0045 + 0.0010  
0.0005 + 0.0005  
0.0005 + 0.0001  
0.0005 + 0.0001  
0.0005 + 0.0001  
0.0005 + 0.0001  
Resistance  
[ 4 ]  
100.0000 Ω  
1 mA  
1 mA  
100 µA  
10 µA  
5 µA  
0.0030 + 0.0030  
0.0020 + 0.0005  
0.0020 + 0.0005  
0.0020 + 0.0005  
0.002 + 0.001  
0.008 + 0.004  
0.008 + 0.001  
0.008 + 0.001  
0.008 + 0.001  
0.008 + 0.001  
0.020 + 0.001  
0.800 + 0.010  
0.010 + 0.004  
0.010 + 0.001  
0.010 + 0.001  
0.010 + 0.001  
0.010 + 0.001  
0.040 + 0.001  
0.800 + 0.010  
0.0006 + 0.0005  
0.0006 + 0.0001  
0.0006 + 0.0001  
0.0006 + 0.0001  
0.0010 + 0.0002  
0.0030 + 0.0004  
0.1500 + 0.0002  
1.000000 kΩ  
10.00000 kΩ  
100.0000 kΩ  
1.000000 MΩ  
10.00000 MΩ  
500 nA  
500 nA || 10 MΩ  
0.015 + 0.001  
0.300 + 0.010  
100.0000 MΩ  
DC Current  
Continuity  
10.00000 mA  
100.0000 mA  
1.000000 A  
3.000000 A  
< 0.1 V  
< 0.6 V  
< 1 V  
0.005 + 0.010  
0.01 + 0.004  
0.05 + 0.006  
0.10 + 0.020  
0.030 + 0.020  
0.030 + 0.005  
0.080 + 0.010  
0.120 + 0.020  
0.050 + 0.020  
0.050 + 0.005  
0.100 + 0.010  
0.120 + 0.020  
0.002 + 0.0020  
0.002 + 0.0005  
0.005 + 0.0010  
0.005 + 0.0020  
< 2 V  
1000.0 Ω  
1 mA  
1 mA  
0.002 + 0.030  
0.002 + 0.010  
0.008 + 0.030  
0.008 + 0.020  
0.010 + 0.030  
0.010 + 0.020  
0.001 + 0.002  
0.001 + 0.002  
Diode Test  
[12]  
1.0000 V  
DC:DC Ratio  
100 mV  
to  
( Input Accuracy ) + ( Reference Accuracy )  
1000 V  
Input Accuracy = accuracy specification for the HI-LO input signal.  
Reference Accuracy = accuracy specification for the HI-LO reference input signal.  
Transfer Accuracy ( typical )  
Conditions:  
( 24 hour % of rangeerror )  
Within 10 minutes and ± 0.5°C.  
Within ±10% of initial value.  
Following a 2-hour warm-up.  
Fixed range between 10% and 100% of full scale.  
2
Using 612 digit slow resolution ( 100 PLC ).  
Measurements are made using accepted metrology practices.  
216  
Chapter 8 Specifications  
DC Characteristics  
Operating Characteristics [ 8 ]  
Measuring Characteristics  
Additional  
Digits Readings/s Noise Error  
DC Voltage  
Measurement Method:  
Function  
DCV, DCI, and  
Resistance  
Continuously integrating, multi-slope III  
A/D converter.  
0.0002% of reading + 0.0001% of range  
612  
612  
512  
512  
412  
0.6 (0.5)  
6 (5)  
60 (50)  
300  
0% of range  
0% of range  
0.001% of range  
0.001% of range  
0.01% of range  
A/D Linearity:  
Input Resistance:  
0.1 V, 1 V, 10 V ranges  
100 V, 1000 V ranges  
Input Bias Current:  
Input Terminals:  
[10]  
[10]  
Selectable 10 Mor >10 G[11]  
10 M±1%  
< 30 pA at 25°C  
Copper alloy  
1000 V on all ranges  
1000  
System Speeds [ 9 ]  
Function Change  
Input Protection:  
26/sec  
Range Change  
Autorange Time  
50/sec  
<30 ms  
55/sec  
1000/sec  
1000/sec  
1000/sec  
900/sec  
Resistance  
Measurement Method:  
Selectable 4-wire or 2-wire ohms.  
Current source referenced to LO input.  
10% of range per lead for 100 , 1 kΩ  
ranges. 1 kper lead on all other ranges.  
1000 V on all ranges  
ASCII readings to RS-232  
ASCII readings to GPIB  
Max. Internal Trigger Rate  
Max. External Trigger Rate to Memory  
Max. External Trigger Rate to GPIB  
Max. Lead Resistance:  
(4-wire ohms)  
Input Protection:  
Autozero OFF Operation  
Following instrument warm-up at calibration temperature ±1°C  
and <10 minutes, add 0.0002% range additional error + 5 µV.  
DC Current  
Shunt Resistor:  
Input Protection:  
0.1for 1A, 3A. 5for 10 mA, 100 mA  
Externally accessible 3A, 250 V fuse  
Internal 7A, 250 V fuse  
Settling Considerations  
Reading settling times are affected by source impedance,  
cable dielectric characteristics, and input signal changes.  
Continuity / Diode Test  
Response Time:  
300 samples/sec with audible tone  
Continuity Threshold:  
Adjustable from 1 to 1000 Ω  
Measurement Considerations  
Agilent recommends the use of Teflon or other high-impedance,  
DC:DC Ratio  
Measurement Method:  
Input HI-LO  
low-dielectric absorption wire insulation for these measurements.  
Input HI-LO / Reference HI-LO  
100 mV to 1000 V ranges  
Reference HI-Input LO 100 mV to 10 V ranges (autoranged)  
[ 1 ] Specifications are for 1-hour warm-up at 612 digits.  
[ 2 ] Relative to calibration standards.  
[ 3 ] 20% overrange on all ranges, except 1000 Vdc, 3 A range.  
[ 4 ] Specifications are for 4-wire ohms function, or 2-wire  
ohms using Math Null. Without Math Null, add 0.2 Ω  
additional error in 2-wire ohms function.  
[ 5 ] For 1 kunbalance in LO lead.  
Input to Reference  
Reference LO to Input LO voltage < 2 V  
Reference HI to Input LO voltage < 12V  
Measurement Noise Rejection  
60 Hz ( 50 Hz ) [ 5 ]  
DC CMRR  
140 dB  
[ 6 ] For power-line frequency ± 0.1%.  
[ 7 ] For power-line frequency ± 1%, subtract 20 dB.  
Integration Time  
Normal Mode Rejection [ 6 ]  
60 dB [ 7 ]  
60 dB [ 7 ]  
60 dB [ 7 ]  
0 dB  
100 PLC / 1.67s (2s)  
10 PLC / 167 ms (200 ms)  
1 PLC / 16.7 ms (20 ms)  
0.2 PLC / 3 ms (3 ms)  
0.02 PLC / 400 µs (400 µs)  
For ± 3%, subtract 30 dB.  
[ 8 ] Readings speeds for 60 Hz and ( 50 Hz ) operation,  
Autozero Off.  
[ 9 ] Speeds are for 412 digits, Delay 0, Autozero OFF,  
and Display OFF. Includes measurement and data  
transfer over GPIB.  
0 dB  
[12] Accuracy specifications are for the voltage measured at  
the input terminals only. 1 mA test current is typical. Variation  
in the current source will create some variation in the voltage  
drop across a diode junction.  
[ 10 ] Add 20 µV for dc volts, 4 µA for dc current, or  
20 mfor resistance.  
[ 11 ] For these ranges, inputs beyond ±17V are  
clamped through 100 k(typical).  
Teflon is a registered trademark of E.I. duPont deNemours and Co.  
8
217  
Chapter 8 Specifications  
AC Characteristics  
AC Characteristics  
Accuracy Specifications ± ( % of reading + % of range ) [ 1 ]  
Temperature  
24 Hour [ 2 ]  
23°C ± 1°C  
1 Year  
23°C ± 5°C  
Coefficient/°C  
0°C – 18°C  
90 Day  
23°C ± 5°C  
Function  
Range [ 3 ]  
Frequency  
28°C – 55°C  
True RMS  
AC Voltage  
[ 4 ]  
100.0000 mV  
3 Hz 5 Hz  
5 Hz 10 Hz  
10 Hz 20 kHz  
20 kHz 50 kHz  
50 kHz 100 kHz  
100 kHz 300 kHz [6]  
1.00 + 0.03  
0.35 + 0.03  
0.04 + 0.03  
0.10 + 0.05  
0.55 + 0.08  
4.00 + 0.50  
1.00 + 0.04  
0.35 + 0.04  
0.05 + 0.04  
0.11 + 0.05  
0.60 + 0.08  
4.00 + 0.50  
1.00 + 0.04  
0.35 + 0.04  
0.06 + 0.04  
0.12 + 0.05  
0.60 + 0.08  
4.00 + 0.50  
0.100 + 0.004  
0.035 + 0.004  
0.005 + 0.004  
0.011 + 0.005  
0.060 + 0.008  
0.20 + 0.02  
1.000000 V  
to  
750.000 V  
3 Hz 5 Hz  
5 Hz 10 Hz  
10 Hz 20 kHz  
20 kHz 50 kHz  
50 kHz 100 kHz [5]  
100 kHz 300 kHz [6]  
1.00 + 0.02  
0.35 + 0.02  
0.04 + 0.02  
0.10 + 0.04  
0.55 + 0.08  
4.00 + 0.50  
1.00 + 0.03  
0.35 + 0.03  
0.05 + 0.03  
0.11 + 0.05  
0.60 + 0.08  
4.00 + 0.50  
1.00 + 0.03  
0.35 + 0.03  
0.06 + 0.03  
0.12 + 0.05  
0.60 + 0.08  
4.00 + 0.50  
0.100 + 0.003  
0.035 + 0.003  
0.005 + 0.003  
0.011 + 0.005  
0.060 + 0.008  
0.20 + 0.02  
True RMS  
AC Current  
[ 4 ]  
1.000000 A  
3.00000 A  
3 Hz 5 Hz  
5 Hz 10 Hz  
10 Hz 5 kHz  
1.00 + 0.04  
0.30 + 0.04  
0.10 + 0.04  
1.00 + 0.04  
0.30 + 0.04  
0.10 + 0.04  
1.00 + 0.04  
0.30 + 0.04  
0.10 + 0.04  
0.100 + 0.006  
0.035 + 0.006  
0.015 + 0.006  
3 Hz 5 Hz  
5 Hz 10 Hz  
10 Hz 5 kHz  
1.10 + 0.06  
0.35 + 0.06  
0.15 + 0.06  
1.10 + 0.06  
0.35 + 0.06  
0.15 + 0.06  
1.10 + 0.06  
0.35 + 0.06  
0.15 + 0.06  
0.100 + 0.006  
0.035 + 0.006  
0.015 + 0.006  
Additional Low Frequency Errors ( % of reading )  
Additional Crest Factor Errors ( non-sinewave ) [ 7 ]  
AC Filter  
Crest Factor  
1 2  
Error ( % of reading )  
0.05%  
Frequency  
Slow  
Medium  
0.74  
0.22  
0.06  
0.01  
0
Fast  
––  
––  
0.73  
0.22  
0.18  
0
10 Hz 20 Hz  
20 Hz 40 Hz  
40 Hz 100 Hz  
100 Hz 200 Hz  
200 Hz 1 kHz  
> 1 kHz  
0
0
0
0
0
0
2 3  
3 4  
4 5  
0.15%  
0.30%  
0.40%  
0
Sinewave Transfer Accuracy ( typical )  
Frequency  
10 Hz 50 kHz  
50 kHz 300 kHz  
Error ( % of range )  
0.002%  
Conditions:  
Sinewave input.  
Within 10 minutes and ± 0.5°C.  
0.005%  
Within ±10% of initial voltage and ±1% of initial frequency.  
Following a 2-hour warm-up.  
Fixed range between 10% and 100% of full scale ( and <120 V ).  
Using 612 digit resolution.  
Measurements are made using accepted metrology practices.  
218  
Chapter 8 Specifications  
AC Characteristics  
Measuring Characteristics  
Operating Characteristics [ 9 ]  
Function  
ACV, ACI  
AC Filter  
Slow  
Medium  
Fast  
Fast  
Fast  
Reading/s  
7 sec/reading  
1
Digits  
612  
Measurement Noise Rejection [ 8 ]  
AC CMRR  
70 dB  
612  
612  
1.6 [ 10 ]  
10  
50 [ 11 ]  
True RMS AC Voltage  
612  
Measurement Method:  
AC-coupled True RMS measures  
the ac component of input with up  
to 400 Vdc of bias on any range.  
Maximum 5:1 at full scale  
612  
System Speeds [ 11 ] , [ 12 ]  
Function or Range Change  
Autorange Time  
ASCII readings to RS-232  
ASCII readings to GPIB  
Max. Internal Trigger Rate  
Max. External Trigger Rate to Memory  
Max. External Trigger Rate to GPIB/RS-232  
Crest Factor:  
AC Filter Bandwidth:  
Slow  
5/sec  
<0.8 sec  
50/sec  
50/sec  
50/sec  
50/sec  
50/sec  
3 Hz 300 kHz  
Medium  
20 Hz 300 kHz  
Fast  
200 Hz 300 kHz  
Input Impedance:  
Input Protection:  
1 MΩ ± 2%, in parallel with 100 pF  
750 V rms all ranges  
True RMS AC Current  
Measurement Method:  
Direct coupled to the fuse and shunt.  
AC-coupled True RMS measurement  
(measures the ac component only).  
0.1 for 1 A and 3 A ranges  
1 A range: < 1 V rms  
[ 1 ] Specifications are for 1-hour warm-up at 612 digits,  
Slow ac filter, sinewave input.  
[ 2 ] Relative to calibration standards.  
Shunt Resistor:  
Burden Voltage:  
3 A range: < 2 V rms  
Externally accessible 3A, 250 V fuse  
Internal 7A, 250 V fuse  
Input Protection:  
[ 3 ] 20% overrange on all ranges, except 750 Vac, 3 A range.  
[ 4 ] Specifications are for sinewave input >5% of range.  
For inputs from 1% to 5% of range and <50 kHz,  
add 0.1% of range additional error. For 50 kHz to 100 kHz,  
add 0.13% of range.  
Settling Considerations  
Applying >300 V rms (or >1 A rms) will cause self-heating in  
signal-conditioning components. These errors are included in  
the instrument specifications. Internal temperature changes  
due to self-heating may cause additional error on lower ac  
voltage ranges. The additional error will be less than 0.02%  
of reading and will generally dissipate within a few minutes.  
[ 5 ] 750 Vac range limited to 100 kHz or 8x107 Volt-Hz.  
[ 6 ] Typically 30% of reading error at 1 MHz.  
[ 7 ] For frequencies below 100 Hz, slow AC filter specified  
for sinewave input only.  
[ 8 ] For 1 kunbalance in LO lead.  
[ 9 ] Maximum reading rates for 0.01% of ac step  
additional error. Additional settling delay required  
when input dc level varies.  
[ 10 ] For External Trigger or remote operation using default  
settling delay ( Delay Auto ).  
[ 11 ] Maximum useful limit with default settling delays defeated.  
[ 12 ] Speeds are for 412 digits, Delay 0, Display OFF, and  
Fast AC filter.  
8
219  
Chapter 8 Specifications  
Frequency and Period Characteristics  
Frequency and Period Characteristics  
Accuracy  
Specifications ± ( % of reading ) [ 1 ]  
Temperature  
Coefficient/°C  
0°C – 18°C  
90 Day  
23°C ± 5°C  
24 Hour [ 2 ]  
23°C ± 1°C  
1 Year  
23°C ± 5°C  
Function  
Range [ 3 ]  
Frequency  
28°C – 55°C  
Frequency,  
Period [ 4 ]  
100 mV  
to  
750 V  
3 Hz 5 Hz  
0.10  
0.05  
0.03  
0.006  
0.10  
0.05  
0.03  
0.01  
0.10  
0.05  
0.03  
0.01  
0.005  
0.005  
0.001  
0.001  
5 Hz 10 Hz  
10 Hz 40 Hz  
40 Hz 300 kHz  
Additional Low-Frequency Errors ( % of reading ) [ 4 ]  
Resolution  
Frequency  
3 Hz 5 Hz  
612  
0
0
512  
0.12  
0.17  
0.2  
412  
0.12  
0.17  
0.2  
5 Hz 10 Hz  
10 Hz 40 Hz  
40 Hz 100 Hz  
100 Hz 300 Hz  
300 Hz 1 kHz  
> 1 kHz  
0
0
0
0
0
0.06  
0.03  
0.01  
0
0.21  
0.21  
0.07  
0.02  
Transfer Accuracy ( typical )  
0.0005% of reading  
Conditions:  
Within 10 minutes and ± 0.5°C.  
Within ±10% of initial value.  
Following a 2-hour warm-up.  
For inputs > 1 kHz and > 100 mV.  
Using 612 digit slow resolution ( 1 second gate time ).  
Measurements are made using accepted metrology practices.  
220  
Chapter 8 Specifications  
Frequency and Period Characteristics  
Measuring Characteristics  
Operating Characteristics [ 5 ]  
Function  
Frequency,  
Period  
Reading/s  
Digits  
612  
Frequency and Period  
Measurement Method:  
1
9.8  
80  
Reciprocal-counting technique.  
AC-coupled input using the  
ac voltage measurement function.  
100 mV rms full scale to 750 V rms.  
Auto or manual ranging.  
512  
412  
Voltage Ranges:  
Gate Time:  
System Speeds [ 5 ]  
Configuration Rates  
Autorange Time  
ASCII readings to RS-232  
ASCII readings to GPIB  
Max. Internal Trigger Rate  
Max. External Trigger Rate to Memory  
Max. External Trigger Rate to GPIB/RS-232  
14/sec  
<0.6 sec  
55/sec  
80/sec  
80/sec  
80/sec  
80/sec  
10 ms, 100 ms, or 1 sec  
Settling Considerations  
Errors will occur when attempting to measure the frequency or  
period of an input following a dc offset voltage change. The input  
blocking RC time constant must be allowed to fully settle ( up to  
1 sec ) before the most accurate measurements are possible.  
Measurement Considerations  
All frequency counters are susceptible to error when  
measuring low-voltage, low-frequency signals. Shielding  
inputs from external noise pickup is critical for minimizing  
measurement errors.  
[ 1 ] Specifications are for 1-hour warm-up at 612 digits.  
[ 2 ] Relative to calibration standards.  
[ 3 ] 20% overrange on all ranges, except 750 Vac range.  
[ 4 ] Input > 100 mV.  
For 10 mV to 100 mV inputs, multiply % of reading  
error x10.  
[ 5 ] Speeds are for 412 digits, Delay 0, Display OFF,  
and Fast AC filter.  
8
221  
Chapter 8 Specifications  
General Information  
General Information  
General Specifications  
Power Supply:  
Power Line Frequency:  
Triggering and Memory  
Reading HOLD Sensitivity:  
Samples per Trigger:  
Trigger Delay:  
External Trigger Delay:  
External Trigger Jitter:  
Memory:  
100 V / 120 V / 220 V / 240 V ±10%.  
45 Hz to 66 Hz and 360 Hz to 440 Hz.  
Automatically sensed at power-on.  
25 VA peak ( 10 W average )  
Full accuracy for 0°C to 55°C  
Full accuracy to 80% R.H. at 40°C  
-40°C to 70°C  
88.5 mm x 212.6 mm x 348.3 mm  
3.6 kg (8 lbs)  
See Delcaration of Conformity  
0.01%, 0.1%, 1%, or 10% of reading  
1 to 50,000  
0 to 3600 sec ( 10 µs step size )  
< 1 ms  
< 500 µs  
512 readings  
Power Consumption:  
Operating Environment:  
Storage Environment:  
Rack Dimensions (HxWxD):  
Weight:  
Math Functions  
Null, Min/Max/Average, dB, dBm, Limit Test (with TTL output).  
dBm reference resistances: 50, 75, 93, 110, 124, 125, 135, 150,  
250, 300, 500, 600, 800, 900, 1000, 1200, or 8000 ohms.  
Safety:  
EMC:  
See Declaration of Conformity  
Standard Programming Languages  
SCPI (Standard Commands for Programmable Instruments)  
Agilent 3478A Language Emulation  
Fluke 8840A, Fluke 8842A Language Emulation  
Vibration and Shock:  
Warranty:  
MIL-T-28800E Type III, Class 5  
(data on file)  
1 year standard  
Accessories Included  
Remote Interface  
Test Lead Kit with probes, alligator, and grabber attachments.  
User’s Guide, Service Guide, test report, and power cord.  
GPIB (IEEE-488.1, IEEE-488.2) and RS-232C  
This ISM device complies with Canadian ICES-001.  
Cet appareil ISM est conforme à la norme NMB-001  
du Canada.  
N10149  
222  
Chapter 8 Specifications  
Product Dimensions  
Product Dimensions  
103.8 mm  
379.4 mm  
261.1 mm  
88. 5 mm  
212. 6 mm  
348. 3 mm  
TOP  
All dimensions are  
shown in millimeters.  
8
223  
Chapter 8 Specifications  
To Calculate Total Measurement Error  
To Calculate Total Measurement Error  
Each specification includes correction factors which account for errors  
present due to operational limitations of the multimeter. This section  
explains these errors and shows how to apply them to your measurements.  
Refer to Interpreting Multimeter Specifications,” starting on page 226,  
to get a better understanding of the terminology used and to help you  
interpret the multimeters specifications.  
The multimeters accuracy specifications are expressed in the form:  
( % of reading + % of range ). In addition to the reading error and range  
error, you may need to add additional errors for certain operating  
conditions. Check the list below to make sure you include all  
measurement errors for a given function. Also, make sure you apply the  
conditions as described in the footnotes on the specification pages.  
If you are operating the multimeter outside the 23°C ± 5°C  
temperature range specified, apply an additional temperature  
coefficient error.  
For dc voltage, dc current, and resistance measurements, you may  
need to apply an additional reading speed error or autozero OFF error.  
For ac voltage and ac current measurements, you may need to apply  
an additional low frequency error or crest factor error.  
Un d er sta n d in g th e “ % of r ea din g ” Er r or The reading error  
compensates for inaccuracies that result from the function and range  
you select, as well as the input signal level. The reading error varies  
according to the input level on the selected range. This error is  
expressed in percent of reading. The following table shows the reading  
error applied to the multimeters 24-hour dc voltage specification.  
Reading Error  
(% of reading)  
Reading  
Error Voltage  
Range  
Input Level  
10 Vdc  
10 Vdc  
10 Vdc  
10 Vdc  
1 Vdc  
0.1 Vdc  
0.0015  
0.0015  
0.0015  
150 µV  
15 µV  
1.5 µV  
224  
Chapter 8 Specifications  
To Calculate Total Measurement Error  
Un der sta n din g the “ % of r a n ge ” Er r or The range error compensates  
for inaccuracies that result from the function and range you select.  
The range error contributes a constant error, expressed as a percent of  
range, independent of the input signal level. The following table shows  
the range error applied to the multimeters 24-hour dc voltage specification.  
Range Error  
(% of range)  
Range  
Error Voltage  
Range  
Input Level  
10 Vdc  
10 Vdc  
10 Vdc  
10 Vdc  
1 Vdc  
0.1 Vdc  
0.0004  
0.0004  
0.0004  
40 µV  
40 µV  
40 µV  
Tota l Mea su r em en t Er r or To compute the total measurement error,  
add the reading error and range error. You can then convert the total  
measurement error to a percent of input” error or a ppm (part-per-  
million) of input” error as shown below.  
Total Measurement Error  
% of input error  
=
× 100  
Input Signal Level  
Total Measurement Error  
Input Signal Level  
ppm of input error =  
× 1,000,000  
Error Example  
Assume that a 5 Vdc signal is input to the multimeter on the 10 Vdc range.  
Compute the total measurement error using the 90-day accuracy  
specifications: ± (0.0020% of reading + 0.0005% of range).  
Reading Error  
Range Error  
Total Error  
= 0.0020% × 5 Vdc  
= 0.0005% × 10 Vdc  
= 100 µV + 50 µV  
= 100 µV  
= 50 µV  
= ± 150 µV  
= ± 0.0030% of 5 Vdc  
= ± 30 ppm of 5 Vdc  
8
225  
Chapter 8 Specifications  
Interpreting Multimeter Specifications  
Interpreting Multimeter Specifications  
This section is provided to give you a better understanding of the terminology  
used and will help you interpret the multimeters specifications.  
Nu m b er of Digit s a n d Over r a n ge  
The number of digits” specification is the most fundamental, and  
sometimes, the most confusing characteristic of a multimeter.  
The number of digits is equal to the maximum number of 9s” the  
multimeter can measure or display. This indicates the number of full  
digits. Most multimeters have the ability to overrange and add a partial  
1
or “ 2” digit.  
For example, the Agilent 34401A can measure 9.99999 Vdc on the 10 V  
range. This represents six full digits of resolution. The multimeter can  
also overrange on the 10 V range and measure up to a maximum of  
12.00000 Vdc. This corresponds to a 612-digit measurement with 20%  
overrange capability.  
Sen sitivity  
Sensitivity is the minimum level that the multimeter can detect for a  
given measurement. Sensitivity defines the ability of the multimeter to  
respond to small changes in the input level. For example, suppose you  
are monitoring a 1 mVdc signal and you want to adjust the level to  
within ±1 µV. To be able to respond to an adjustment this small, this  
measurement would require a multimeter with a sensitivity of at least 1 µV.  
You could use a 612-digit multimeter if it has a 1 Vdc or smaller range.  
You could also use a 412-digit multimeter with a 10 mVdc range.  
For ac voltage and ac current measurements, note that the smallest  
value that can be measured is different from the sensitivity. For the  
Agilent 34401A, these functions are specified to measure down to 1% of  
the selected range. For example, the multimeter can measure down to  
1 mV on the 100 mV range.  
226  
Chapter 8 Specifications  
Interpreting Multimeter Specifications  
Resolu tion  
Resolution is the numeric ratio of the maximum displayed value divided  
by the minimum displayed value on a selected range. Resolution is  
often expressed in percent, parts-per-million (ppm), counts, or bits.  
For example, a 612-digit multimeter with 20% overrange capability can  
display a measurement with up to 1,200,000 counts of resolution.  
This corresponds to about 0.0001% (1 ppm) of full scale, or 21 bits  
including the sign bit. All four specifications are equivalent.  
Accu r a cy  
Accuracy is a measure of the exactness” to which the multimeters  
measurement uncertainty can be determined relative to the calibration  
reference used. Absolute accuracy includes the multimeters relative  
accuracy specification plus the known error of the calibration reference  
relative to national standards (such as the U.S. National Institute of  
Standards and Technology). To be meaningful, the accuracy specifications  
must be accompanied with the conditions under which they are valid.  
These conditions should include temperature, humidity, and time.  
There is no standard convention among multimeter manufacturers for  
the confidence limits at which specifications are set. The table below  
shows the probability of non-conformance for each specification with the  
given assumptions.  
Specification  
Criteria  
Probability  
of Failure  
Mean ± 2 sigma  
Mean ± 3 sigma  
Mean ± 4 sigma  
4.5%  
0.3%  
0.006%  
Variations in performance from reading to reading, and instrument to  
instrument, decrease for increasing number of sigma for a given  
specification. This means that you can achieve greater actual measurement  
precision for a specific accuracy specification number.  
The Agilent 34401A is designed and tested to meet performance better  
than mean ±4 sigma of the published accuracy specifications.  
8
227  
Chapter 8 Specifications  
Interpreting Multimeter Specifications  
Tr a n sfer Accu r a cy  
Transfer accuracy refers to the error introduced by the multimeter  
due to noise and short-term drift. This error becomes apparent when  
comparing two nearly-equal signals for the purpose of transferring”  
the known accuracy of one device to the other.  
24-Hou r Accu r a cy  
The 24-hour accuracy specification indicates the multimeters relative  
accuracy over its full measurement range for short time intervals and  
within a stable environment. Short-term accuracy is usually specified  
for a 24-hour period and for a ±1°C temperature range.  
90-Da y a n d 1-Yea r Accu r a cy  
These long-term accuracy specifications are valid for a 23°C ± 5°C  
temperature range. These specifications include the initial calibration  
errors plus the multimeters long-term drift errors.  
Tem p er a tu r e Coefficien t s  
Accuracy is usually specified for a 23°C ± 5°C temperature range.  
This is a common temperature range for many operating environments.  
You must add additional temperature coefficient errors to the accuracy  
specification if you are operating the multimeter outside a 23°C ± 5°C  
temperature range (the specification is per °C).  
228  
Chapter 8 Specifications  
Configuring for Highest Accuracy Measurements  
Configuring for Highest Accuracy Measurements  
The measurement configurations shown below assume that the  
multimeter is in its power-on or reset state. It is also assumed that  
manual ranging is enabled to ensure proper full scale range selection.  
DC Volta ge, DC Cu r r en t, a n d Resista n ce Mea su r em en ts:  
Set the resolution to 6 digits (you can use the 6 digits slow mode for  
further noise reduction).  
Set the input resistance to greater than 10 G(for the 100 mV, 1 V,  
and 10 V ranges) for the best dc voltage accuracy.  
Use 4-wire ohms for the best resistance accuracy.  
Use Math Null to null the test lead resistance for 2-wire ohms, and to  
remove interconnection offset for dc voltage measurements.  
AC Volta ge a n d AC Cu r r en t Mea su r em en ts:  
Set the resolution to 6 digits.  
Select the slow ac filter (3 Hz to 300 kHz).  
Fr equ en cy a n d P er iod Mea su r em en ts:  
Set the resolution to 6 digits.  
8
229  
230  
Index  
If you have questions relating to the operation of the multimeter,  
call 1-800-452-4844 in the United States, or contact your nearest  
Agilent Sales Office.  
12” digit, 21, 54  
command  
compliance (SCPI), 168  
average (min-max) measurements  
beeper control, 88  
description, 39, 64  
front-panel, 39  
functions allowed, 63, 124  
2-wire ohms  
summary, 105-111  
syntax conventions, 50, 105, 155  
common commands, 169  
common mode rejection (CMR), 201  
complete self-test, 13, 86  
CONFigure, 113, 119  
preset state, 110  
Conformity, Declaration, 237  
connections  
2-wire ohms, 17  
4-wire ohms, 17  
ac current, 18  
ac volts, 17  
continuity, 19  
dc current, 18  
dc volts, 17  
dcv:dcv ratio, 44  
diode, 19  
frequency, 18  
period, 18  
connectors  
Ext Trig, 5, 83  
GPIB interface, 5  
RS-232 interface, 5  
VM Comp, 5, 83  
continuity  
connections, 19  
current source, 19  
math functions allowed, 63, 124  
threshold resistance, 52  
crest factor error, 207, 224  
current  
ac current  
connections, 18  
math functions allowed, 63, 124  
ranges, 18  
signal filter, 51, 214  
dc current  
See two-wire ohms  
34398A Cable Kit, 149  
34399A Adapter Kit, 149  
3478A compatibility, 166  
34812A BenchLink Software, 1  
4-wire ohms  
B
See four-wire ohms  
9.90000000E+37, 61, 131  
bandwidth detector, 51, 214  
bandwidth error, 208  
baud rate, 93, 148, 151, 163  
beeper  
A
continuity threshold, 19  
diode threshold, 19  
enable/disable, 88  
BenchLink software (34812A), 1  
BNC connectors  
Ext Trig, 5, 83  
VM Comp, 5, 83  
boolean parameters, 159  
bumpers, removing, 23  
burden voltage, 205, 212  
bus triggering, 75, 127  
a/d convertor, 55, 57  
abort measurement, 76  
ac bandwidth detector, 51, 214  
ac current  
connections, 18  
math functions allowed, 63, 124  
ranges, 18  
signal filter, 51, 214  
ac settling times, 51  
ac signal filter, 51, 214  
ac voltage  
connections, 17  
loading errors, 209  
math functions allowed, 63, 124  
ranges, 17  
C
cables (RS-232), 150  
CALCulate:FUNCtion, 63, 124  
CALCulate:STATe, 63, 124  
CALibration:COUNt?, 98, 146  
CALibration:SECure, 97, 146  
CALibration:STRing, 99, 147  
calibration  
signal filter, 51, 214  
accessories included, 13, 222  
accuracy, highest, 229  
adapters (RS-232), 149  
address, GPIB, 91, 161  
addressed commands (IEEE-488), 169  
Agilent Express, 6  
alternate language compatibility  
Agilent 3478A, 166  
Fluke 8840A/8842A, 167  
annunciators, 4  
aperture time, 58  
automatic trigger delays, 81  
autoranging  
front-panel key, 20  
threshold values, 20, 61  
auto trigger, 42, 73  
autozero  
definition, 59, 213  
vs. integration time, 59  
vs. resolution, 59  
changing security code, 98  
commands, 146  
count, 98  
errors, 180  
message, 99  
secure procedure, 97  
security code, factory setting, 95  
unsecure procedure, 96  
carrying handle  
adjusting, 16  
removing, 23  
connections, 18  
math functions allowed, 63, 124  
measurement errors, 205  
ranges, 18  
chassis ground, 5  
CLEAR, 76  
comma separator, 37, 89  
current input fuses, replacing, 100  
current source  
continuity, 19  
diode, 19  
231  
Index  
diode  
beeper control, 88  
beeper threshold, 19  
connections, 19  
current source, 19  
math functions allowed, 63, 124  
display  
annunciators, 4  
comma separator, 37, 89  
enable/disable, 87  
formats, 22  
D
F
DATA:FEED, 65, 126, 130  
DATA:FEED?, 65, 126, 130  
DATA:POINts?, 84, 133  
data logging to printer, 91, 160  
data types (SCPI), 158  
data formats, output, 159  
dB measurements  
fast ac filter, 51, 214  
FETCh?, 115, 132  
filler panel kit, 24  
filter, ac signal, 51, 214  
firmware revision query, 89  
fixed range, 61  
fixed input resistance, 53  
flange kit, 24  
flowchart (triggering), 72  
Fluke 8840A/8842A compatibility, 167  
format, output data, 159  
four-wire ohms  
description, 40, 67  
front-panel, 40  
functions allowed, 63, 124  
relative value, 40, 67  
dBm measurements  
description, 41, 68  
message, 87  
DISPlay:TEXT, 87, 132  
DISPlay:TEXT:CLEar, 87, 132  
DTR/DSR handshake, 151  
connections, 17  
math functions allowed, 63, 124  
front-panel, 41  
functions allowed, 63, 124  
resistance values, 41, 68  
dc current  
ranges, 17  
FREQuency:APERture, 58, 122  
frequency  
aperture time, 58  
connections, 18  
math functions allowed, 63, 124  
measurement band, 18  
front panel  
annunciators, 4  
beeper, 88  
comma separator, 37, 89  
display formats, 22  
enable/disable, 87  
menu  
examples, 31-36  
messages displayed, 30  
overview, 3  
quick reference, 27-28  
tree diagram, 29  
messages, front-panel, 87  
front-panel keys  
menu, 29  
range, 20  
resolution, 21  
trigger, 42  
Front/Rear switch, 2, 58  
fuses  
E
enable register  
clearing, 136, 141, 143  
definition, 134  
connections, 18  
math functions allowed, 63, 124  
measurement errors, 205  
ranges, 18  
dc input resistance, 53  
dc voltage  
connections, 17  
input resistance, 53  
loading errors, 199  
math functions allowed, 63, 124  
ranges, 17  
dcv:dcv ratio measurements  
connections, 44  
front panel, 44  
math functions allowed, 63, 124  
selecting, 45  
Declaration of Conformity, 237  
delay  
error messages  
calibration errors, 180  
error queue, 85, 172  
error string length, 85, 172  
execution errors, 173  
self-test errors, 179  
errors  
bandwidth, 208  
burden voltage, 212  
common mode, 212  
crest factor, 207, 224  
leakage current, 199  
service request generation, 69, 137  
temperature coefficient, 224  
test lead resistance, 204  
thermal EMF, 198  
EOI (end-or-identify), 157  
even parity, 93  
settling, 204  
trigger, 79  
DETector:BANDwidth, 51, 123  
detector bandwidth, 51, 214  
device clear, 152, 157, 160  
dielectric absorption, 204  
digits, number of, 54, 226  
dimensions, product, 223  
discrete parameters, 158  
event register  
clearing, 141, 143  
definition, 134  
examples  
current input, 5, 100  
power-line, 14, 100  
fuse-holder assembly, 5, 15  
CONFigure, 116  
front-panel menu, 31-36  
MEASure?, 115  
Ext Trig terminal, 5, 83  
external trigger, 42, 74, 83  
232  
Index  
input terminals  
Front/Rear switch, 2, 58  
query setting, 58  
input message terminators, 157  
integration time  
definition, 57  
vs. autozero, 59, 60  
vs. resolution, 54, 57, 59  
interface (remote)  
G
M
gate time, 58  
GPIB (IEEE-488)  
address  
magnetic loops, 201  
maintenance, 100  
manual range, 20, 61  
math operations  
displayed at power-on, 13  
factory setting, 91  
setting the, 91, 161  
TALK ONLY mode, 91, 160  
compliance information, 168  
connector location, 5  
description, 63, 124  
functions allowed, 63, 124  
MEASure?, 113, 117  
preset state, 112  
measurement band  
frequency, 18  
GPIB connector, 5  
GPIB selection, 92, 162  
language restrictions, 92, 94  
RS-232 connector, 5, 150  
RS-232 selection, 92, 162  
internal reading memory  
functions allowed, 46, 84  
number of readings stored, 84  
retrieving readings, 46  
storing readings, 46  
selecting interface, 92, 162  
ground, chassis, 5  
ground loop noise, 202  
Group Execute Trigger (GET), 75  
period, 18  
measurement errors, 224  
measurement function  
math combinations allowed, 63, 124  
measurement range  
autoranging, 20, 61  
front-panel keys, 20  
overload, 61, 142  
selecting, 20  
measurement ranges  
2-wire ohms, 17  
4-wire ohms, 17  
ac current, 18  
ac volts, 17  
dc current, 18  
dc volts, 17  
dcv:dcv ratio, 44  
frequency, 18  
period, 18  
measurement resolution  
front-panel keys, 21  
half” digit, 21, 54  
setting, 21  
power line cycles, 54  
vs. autozero, 59  
vs. integration time, 54  
measurement terminals  
Front/Rear switch, 2, 58  
query setting, 58  
measurement tutorial, 197  
medium ac filter, 51, 214  
memory, internal  
functions allowed, 46, 84  
number of readings stored, 84  
retrieving readings, 46  
storing readings, 46  
H
half” digit, 21, 54  
hardware lines (IEEE-488), 169  
handle  
internal triggering, 75  
adjusting, 16  
removing, 23  
L
hardware, rack mounting, 24  
hardware handshake (RS-232), 151  
HP-IB (See GPIB)  
L1, L2, L3, 94, 166  
language  
command summary, 105-111  
compatibility, 166  
compliance (SCPI), 168  
restrictions, 92, 94  
selecting, 94, 162  
lead resistance, 38, 65, 204  
leakage current errors, 199  
limit test  
I
identification string, 89  
idle trigger state, 76, 129  
*IDN?, 89  
IEEE-488 (GPIB)  
address  
displayed at power-on, 13  
factory setting, 91  
beeper control, 88  
description, 69  
setting the, 91, 161  
TALK ONLY mode, 91, 160  
compliance information, 168  
connector location, 5  
selecting interface, 92, 162  
induced voltages, 201  
INITiate, 115, 130  
input bias current, 199  
INPut:IMPedance:AUTO, 53, 123  
input message terminators, 157  
input resistance, dc volts, 53  
input signal range  
functions allowed, 63, 124  
RS-232 pass/fail outputs, 70  
service request, 69, 142  
line frequency noise, 57  
line voltage  
factory setting, 14  
selector module, 15  
setting the, 15  
loading errors  
ac volts, 209  
dc volts, 53, 199  
lock-link kit, 24  
frequency, 18  
period, 18  
233  
Index  
menu  
examples, 31-36  
overview, 3  
messages displayed, 30  
quick reference, 27-28  
tree diagram, 29  
messages displayed  
front-panel, 87  
menu, 30  
message terminators, 157  
min-max measurements  
beeper control, 88  
description, 39, 63  
front-panel, 39  
power-line fuse  
factory configuration, 14  
installation, 15  
power-line noise, rejecting, 200  
power-line voltage  
factory setting, 14  
selector module, 15  
setting the, 15  
power-on  
self-test, 13  
sequence, 13  
state, 101  
product dimensions, 223  
product specifications, 215  
programming language  
command summary, 105-111  
compatibility, 166  
compliance (SCPI), 168  
restrictions, 92, 94  
selecting, 94, 165  
O
odd parity, 93  
offset (null) measurements  
description, 38, 65  
front panel, 38  
functions allowed, 63, 124  
Null Register, 38, 66  
null test lead resistance, 38, 65, 204  
offset voltages, 59, 196  
ohms  
2-wire  
connections, 17  
math functions allowed, 63, 124  
ranges, 17  
4-wire  
connections, 17  
math functions allowed, 63, 124  
ranges, 17  
functions allowed, 63, 124  
N
noise  
ground loop, 202  
*OPC,137  
operator maintenance, 100  
output data format, 159  
output buffer, 139  
overload, 61, 142  
OVLD, 61, 142  
magnetic loops, 201  
power-line voltage, 200  
noise pickup, 53, 199  
noise rejection, 21, 57, 200  
no parity, 93  
normal mode rejection (NMR), 57, 200  
NPLC, 54, 57, 200  
null measurements  
description, 38, 65  
pushbuttons (front panel), 2  
Q
questionable data register  
bit definitions, 142  
clearing, 143  
P
parameter types, 158  
parity, 93, 164  
R
front panel, 38  
parts-per-million, 227  
pass/fail limit test  
rack mounting  
bumpers, removing, 23  
carrying handle, removing, 23  
filler panel kit, 24  
flange kit, 24  
functions allowed, 63, 124  
Null Register, 38, 66  
null test lead resistance, 38, 65, 204  
number of digits, 54, 226  
number of readings, 77  
numeric parameters, 158  
beeper control, 88  
description, 69  
functions allowed, 63, 124  
RS-232 pass/fail outputs, 70  
service request, 69, 142  
PERiod:APERture, 58, 122  
period  
lock-link kit, 24  
sliding-shelf kit, 24  
ranges  
2-wire ohms, 17  
4-wire ohms, 17  
ac current, 18  
ac volts, 17  
dc current, 18  
dc volts, 17  
dcv:dcv ratio, 44  
frequency, 18  
period, 18  
aperture time, 58  
connections, 18  
math functions allowed, 63, 124  
measurement band, 18  
power cord, 15  
power dissipation effects, 204  
power line cycles, 54, 57, 200  
power-line frequency  
power-on sensing, 200  
234  
Index  
ranging  
autoranging, 20, 61  
resistance  
2-wire  
security code (calibration)  
changing, 98  
front-panel keys, 20  
overload, 61, 142  
selecting, 20  
connections, 17  
math functions allowed, 63, 124  
ranges, 17  
factory setting, 95  
rules, 95  
string length, 95  
ratio (dcv:dcv) measurements  
4-wire  
self-heating errors, 210  
connections, 44  
connections, 17  
self-test  
front panel, 44  
math functions allowed, 63, 124  
selecting, 45  
READ?, 114, 130  
reading hold  
math functions allowed, 63, 124  
ranges, 17  
resistance, input, 53  
resolution  
complete test, 13, 86  
errors, 179  
reading memory, 84, 86  
power-on test, 13, 86  
sensitivity, 226  
front-panel keys, 21  
beeper control, 88  
description, 43, 82  
front-panel, 43  
sensitivity band, 43, 82  
half” digit, 21, 54  
power line cycles, 54  
setting, 21  
vs. autozero, 59  
sensitivity band (reading hold), 43, 82  
serial interface (RS-232)  
baud rate selection, 93, 148, 163  
cables recommended, 95, 150  
commands, 153  
connector location, 5, 150  
connector pinout, 150  
data format, 159  
handshake protocol (DTR/DSR), 151  
parity selection, 93, 164  
pass/fail outputs, 70, 150  
pin definitions, 150  
selecting interface, 92, 162  
TALK ONLY mode, 91, 160  
serial poll, 137  
service request (SRQ), 69, 137  
settling  
delays, 204  
trigger, 79  
signal filter, 51, 214  
single trigger, 42, 73  
sliding-shelf kit, 24  
slow ac filter, 51, 214  
software (bus) triggering, 75, 127  
specifications, 215  
standard event register  
bit definitions, 140  
clearing, 141  
reading memory  
vs. integration time, 54  
retrieving stored readings, 46  
revision query (firmware), 89  
ROUTe:TERMinals?, 58, 123  
RS-232 interface  
baud rate selection, 93, 148, 163  
cables recommended, 150  
commands, 153  
connector location, 5, 150  
connector pinout, 150  
data format, 159  
handshake protocol (DTR/DSR), 151  
parity selection, 93, 164  
pass/fail outputs, 70, 150  
pin definitions, 150  
functions allowed, 46, 84  
number of readings stored, 84  
retrieving readings, 46  
storing readings, 46  
readings, number of, 77  
rear panel  
input terminals, 5  
pictorial overview, 5  
rear terminals  
query setting, 58, 123  
selecting, 58  
reciprocal counting technique, 213  
register diagram (status), 135  
regulatory requirements, 237  
relative value (dB), 40, 67  
relative measurements  
description, 38, 65  
selecting interface, 92, 162  
TALK ONLY mode, 91, 160  
rubber bumpers, removing, 23  
front panel, 38  
functions allowed, 63, 124  
Null Register, 38, 66  
null test lead resistance, 38, 65, 204  
remote interface  
S
SAMPle:COUNt, 77, 131  
samples, number of, 77  
SCPI  
command summary, 105-111  
compliance information, 168  
data types, 158  
language introduction, 154  
status model, 134  
syntax conventions, 50, 105, 155  
version query, 90, 133  
GPIB connector, 5  
GPIB selection, 92, 162  
language restrictions, 92, 94  
RS-232 connector, 5, 150  
RS-232 selection, 92, 162  
replacing fuses, 100  
reset state, 101  
status byte  
bit definitions, 136  
clearing, 136  
summary register, 136  
235  
Index  
status register  
test  
complete self-test, 13, 86  
V
commands, 144  
description, 134  
diagram, 135  
enable register, 134  
event register, 134  
*STB?, 138, 145  
stop bits, 148  
vacuum-fluorescent display, 1  
version  
firmware, 89  
power-on self-test, 13, 86  
reading memory, 84, 86  
self-test errors, 179  
test lead resistance, 38, 64, 198  
thermal EMF errors, 198  
threshold resistance, continuity, 52  
transfer accuracy, 228  
*TRG, 75  
SCPI, 90  
VM Comp terminal, 5, 83  
voltage  
ac voltage  
connections, 17  
loading errors, 209  
math functions allowed, 63, 124  
ranges, 17  
signal filter, 51, 214  
dc voltage  
connections, 17  
input resistance, 53  
loading errors, 199  
math functions allowed, 63, 124  
ranges, 17  
storing readings  
functions allowed, 46, 84  
number of readings stored, 84  
retrieving readings, 46  
storing readings, 46  
string length  
calibration message, 99  
displayed message, 87  
error queue, 85  
identification string, 89  
string parameters, 159  
summary register  
clearing, 136  
definition, 136  
TRIGGER, 75  
TRIGger:COUNt, 78, 131  
TRIGger:DELay, 80, 131  
TRIGger:DELay:AUTO, 80, 131  
TRIGger:SOURce, 73, 130  
triggering  
abort measurements, 76  
auto trigger, 42, 73  
commands, 130  
delay, 79  
external trigger, 42, 74, 83  
flowchart, 72  
voltage selector module, 15  
Voltmeter Complete terminal, 5, 83  
support-shelf kit, 24  
syntax conventions, 50, 105, 155  
SYSTem:BEEPer, 88, 133  
SYSTem:ERRor?, 85, 133  
front-panel, 42  
idle trigger state, 76, 129  
internal, 75  
W
wait-for-trigger” state, 76, 129  
warranty information, inside front cover  
weight, product, 222  
wiring adapter (RS-232), 149  
wiring connections  
2-wire ohms, 17  
4-wire ohms, 17  
ac current, 18  
multiple readings (samples), 77  
multiple triggers, 78  
single trigger, 42, 73  
software (bus) trigger, 75, 127  
sources, 73  
“wait-for-trigger” state, 76, 129  
*TST?, 86  
tutorial  
front-panel menu, 29  
measurement, 197  
twisted-pair connections, 201  
two-wire ohms  
connections, 17  
T
TALK ONLY mode, 91, 92, 160  
temperature coefficient, 210, 224, 228  
terminals  
Ext Trig, 5, 83  
Front/Rear switch, 2, 58  
GPIB interface, 5  
query setting, 58  
RS-232 interface, 5  
ac volts, 17  
continuity, 19  
dc current, 18  
dc volts, 17  
dcv:dcv ratio, 44  
diode, 19  
frequency, 18  
VM Comp, 5, 83  
terminators, input message, 157  
math functions allowed, 63, 124  
ranges, 17  
period, 18  
Z
zero measurements, 59, 213  
236  

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