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 ("}Ω 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.

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

DECLARATION OF CONFORMITY

According to ISO/IEC Guide 22 and CEN/CENELEC EN 45014

Manufacturer’s Name:

Manufacturer’s Address:

Agilent Technologies, Incorporated

815 – 14^thSt. 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 6¹⁄₂-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^®

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

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.

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

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.

The Rear Panel at a Glance

Chassis Ground

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).

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 multimeter’s 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

multimeter’s 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 multimeter’s 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.

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

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

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

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

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.

Chapter 1 Quick Start

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 User’s 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.

Chapter 1 Quick Start

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 multimeter’s 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.

Chapter 1 Quick Start

If the Multimeter Does Not Turn On

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.

Chapter 1 Quick Start

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

Chapter 1 Quick Start

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 kΩ, 10 kΩ, 100 kΩ, 1 MΩ, 10 MΩ, 100 MΩ

Maximum resolution: 100 µΩ (on 100 ohm range)

Chapter 1 Quick Start

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

Chapter 1 Quick Start

To Test Continuity

Test current source: 1 mA

Maximum resolution: 0.1 Ω (range is fixed at 1 kohm)

Beeper threshold: 1 Ω to 1000 Ω (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 ≤ V_measured≤ 0.8 volts (not adjustable)

Chapter 1 Quick Start

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 signal’s input voltage, not its frequency.

The range is fixed for continuity (1 kΩ range) 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.

Chapter 1 Quick Start

To Set the Resolution

You can set the display resolution to 4¹⁄₂, 5¹⁄₂, or 6¹⁄₂digits either to

optimize measurement speed or noise rejection. In this book, the most

significant digit (leftmost on the display) is referred to as the “¹⁄₂” digit,

since it can only be a “0” or “1.”

Press the Shift key.

Selects 4¹⁄₂digits.

Selects 5¹⁄₂digits.

Selects 6¹⁄₂digits (most noise rejection).

•

The resolution is set to 5¹⁄₂digits at power-on and after a remote

interface reset.

•

The resolution is fixed at 5¹⁄₂digits 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

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.

Chapter 1 Quick Start

Front-Panel Display Formats

–

Negative sign or blank (positive)

“ ¹⁄₂” digit (0 or 1)

Numeric digits

-H.DDD,DDD EFFF

Exponent ( m, k, M )

Measurement units ( VDC, OHM, HZ, dB )

Front-panel display format.

5 digits

10.216,5 VDC

“¹⁄₂” digit

This is the 10 Vdc range, 5¹⁄₂digits are displayed.

“¹⁄₂” digit

-045.23

mVDC

This is the 100 mVdc range, 4¹⁄₂digits are displayed.

113.325,6 OHM

This is the 100 ohm range, 6¹⁄₂digits are displayed.

OVL.D

mVDC

This is an overload indication on the 100 mVdc range.

Chapter 1 Quick Start

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.

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).

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 multimeter’s capabilities

and operation.

Chapter 2 Front-Panel Menu Operation

Front-Panel Menu Reference

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 Ω to 1000 Ω).

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.

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.

Chapter 2 Front-Panel Menu Operation

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.

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

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

to view the choices.

COMMANDS You are on the “commands” level. Press

command choices within the selected menu group.

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.

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

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

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).

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

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

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.

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

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 5¹⁄₂digits 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

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.

∧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

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.

Chapter 2 Front-Panel Menu Operation

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.

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

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.

Chapter 2 Front-Panel Menu Operation

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.

Chapter 2 Front-Panel Menu Operation

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.

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.

Chapter 2 Front-Panel Menu Operation

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.

Chapter 2 Front-Panel Menu Operation

To Make dBm Measurements

The dBm operation calculates the power delivered to a resistance

referenced to 1 milliwatt.

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 Ω. 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.

Chapter 2 Front-Panel Menu Operation

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.

Chapter 2 Front-Panel Menu Operation

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.

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.

Chapter 2 Front-Panel Menu Operation

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.

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 .

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.

Chapter 2 Front-Panel Menu Operation

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

Chapter 2 Front-Panel Menu Operation

To Use Reading Memory

∨

Move d ow n a level a n d t h en a cr oss t o t h e “ON” ch oice.

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

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

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

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.

Chapter 3 Features and Functions

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.

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}

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 Ω and 1000 Ω.

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 Ω.

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.

Chapter 3 Features and Functions

Measurement Configuration

DC In p u t R esist a n ce

Normally, the multimeter’s input resistance is fixed at 10 MΩ for 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 GΩ for the 100 mVdc, 1 Vdc, and 10 Vdc ranges.

Applies to dc voltage measurements and is disabled for all other functions.

Input Resistance

100mV, 1V, 10V ranges

100V, 1000V ranges

Fixed Resistance ON (default)

10 MΩ

> 10 GΩ

10 MΩ

Fixed Resistance OFF

•

The input resistance setting is stored in volatile memory; the

multimeter selects 10 MΩ (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 MΩ mode (fixed

resistance for all dc voltage ranges) or the >10 GΩ mode. The default

is 10 MΩ.

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 MΩ for all ranges. With AUTO ON, the input resistance

is set to >10 GΩ for the three lowest dc voltage ranges. The CONFigure

and MEASure?commands automatically turn AUTO OFF.

INPut:IMPedance:AUTO {OFF|ON}

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 “¹⁄₂” digit which can only be a “0” or “1”. To increase measurement

accuracy and improve noise rejection, select 6¹⁄₂digits. To increase

measurement speed, select 4¹⁄₂digits.

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.

Chapter 3 Features and Functions

Measurement Configuration

5 digits

10.216,5 VDC

“¹⁄₂” digit

This is the 10 Vdc range, 5¹⁄₂digits are displayed.

“¹⁄₂” digit

-045.23 mVDC

This is the 100 mVdc range, 4¹⁄₂digits are displayed.

113.325,6 OHM

This is the 100 ohm range, 6¹⁄₂digits are displayed.

•

The resolution is stored in volatile memory; the multimeter sets the

resolution to 5¹⁄₂digits (for all functions) when power has been off or

after a remote interface reset.

•

The resolution is fixed at 5¹⁄₂digits 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 multimeter’s

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 6¹⁄₂digits.

If you select 4¹⁄₂digits or 5¹⁄₂digits, 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.

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

4¹⁄₂digits on the 10 Vdc range

6¹⁄₂digits on the 1 A range

1000 Hz input, 0.1 Hz resolution

50 mV resolution on the ac function

Chapter 3 Features and Functions

Measurement Configuration

In tegr a t ion Tim e

Integration time is the period during which the multimeter’s 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.

•

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

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 (4¹⁄₂digits), 100 m s

(default; 5¹⁄₂digits), or 1 second (6¹⁄₂digits).

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”

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 multimeter’s 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.

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

0.2 PLC

10 PLC

Off

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.

•

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}

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.

From 34401A Specifications:

Remote

Configuration Front-Panel Equivalent

Digits Displayed Readings/Sec

NPLC: 100

Slow 6 digits

N/A

6¹⁄₂

N/A

6¹⁄₂

N/A

5¹⁄₂

N/A

5¹⁄₂

N/A

4¹⁄₂

Autozero: On

Digits Displayed: 6¹⁄₂

NPLC: 100

Autozero: Off

Digits Displayed: 6¹⁄₂

NPLC: 10

Autozero: On

Digits Displayed: 6¹⁄₂

NPLC: 10

Autozero: Off

Digits Displayed: 6¹⁄₂

NPLC: 1

Autozero: On

Digits Displayed: 5¹⁄₂

NPLC: 1

Autozero: Off

Digits Displayed: 5¹⁄₂

NPLC: 0.2

Autozero: On

Digits Displayed: 5¹⁄₂

NPLC: 0.2

Autozero: Off

Digits Displayed: 5¹⁄₂

NPLC: 0.02

N/A

0.6

Fast 6 digits

Slow 5 digits

N/A

Slow 4 digits

N/A

300

N/A

1000

Fast 5 digits

N/A

Autozero: On

Digits Displayed: 4¹⁄₂

NPLC: 0.02

Fast 4 digits

Autozero: Off

Digits Displayed: 4¹⁄₂

See the Agilent 34401A specifications listed on page 217.

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.

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 kΩ range) 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.

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 signal’s

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}

Chapter 3 Features and Functions

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.

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

Ω 2W

Ω 4W

Null

Min-Max

dBm

Limit

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

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 “MAX” and 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 multimeter’s 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.

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

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.

Chapter 3 Features and Functions

Math Operations

Null (Relative)

(continued)

•

The null value is stored in the multimeter’s 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

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.

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 multimeter’s 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

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.

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 600Ω.

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}

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.

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).

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.

5 V

0 V

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.

Chapter 3 Features and Functions

Triggering

The multimeter’s 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.

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 multimeter’s triggering system.

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

Trigger

Count ≠ 1 Count ≠ 1

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.

•

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.

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

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

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

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.

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.

•

Front-Panel Operation:

3: N SAMPLES (TRIG MENU)

Remote Interface Operation:

SAMPle:COUNt {<value>|MINimum|MAXimum}

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}

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.

•

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 ---

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}

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

•

Resistance (2-wire and 4-wire):

Trigger Delay

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

10 ms

1.5 ms

15 ms

10 MΩ

100 MΩ

10 MΩ

100 MΩ

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

1.0 sec

0 sec

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 MΩ (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.

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

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

Chapter 3 Features and Functions

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.

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 multimeter’s 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”.

•

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"

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.

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.

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’"

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

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

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.

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).

Chapter 3 Features and Functions

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 multimeter’s 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.

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 controller’s 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.

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

Not allowed

SCPI Language

3478A Language

Fluke 8840A Language

•

Front-Panel Operation:

2: INTERFACE (I/O MENU)

See also “To Select the Remote Interface,” on page 162.

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.

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.

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

SCPI Language

3478A Language

Fluke 8840A Language

Not allowed

•

Front-Panel Operation:

5: LANGUAGE (I/O MENU)

See also “To Select the Programming Language,” on page 165.

Remote Interface Operation:

select SCPI language

select Agilent 3478A language

select Fluke 8840A language

Chapter 3 Features and Functions

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.

•

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.

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"

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)

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"

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?

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 multimeter’s 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.

•

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’"

Chapter 3 Features and Functions

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 multimeter’s 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 multimeter’s case by loosening three screws. See the

Service Guide for more information on disassembling the multimeter.

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Chapter 3 Features and Functions

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)

•

Continuity Threshold

10 Ω

Function

DC volts

Input Resistance

Integration Time

Range

10 MΩ (fixed for all dcv ranges)

10 PLCs

Autorange

5¹⁄₂digits, slow mode

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

Reading Memory

Off (cleared)

Input/Output

Configuration

Power-On/Reset State

•

Baud Rate

GPIB Address

Interface

Language

Parity

9600 baud

GPIB (IEEE-488)

SCPI

Even (7 data bits)

Calibration

Calibration State

Power-On/Reset State

Secured

•

101

102

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.

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Chapter 4 Remote Interface Reference

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)

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?

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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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Chapter 4 Remote Interface Reference

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]

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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Chapter 4 Remote Interface Reference

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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Chapter 4 Remote Interface Reference

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]

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

SYSTem

:BEEPer

:BEEPer:STATe {OFF|ON}

:BEEPer:STATe?

Default parameters are shown in bold.

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Chapter 4 Remote Interface Reference

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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Chapter 4 Remote Interface Reference

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

*OPC?

*PSC {0|1}

*PSC?

*RST

*SRE <enable value>

*SRE?

*STB?

*TRG

*TST?

Default parameters are shown in bold.

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Chapter 4 Remote Interface Reference

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 multimeter’s 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 MΩ for 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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Chapter 4 Remote Interface Reference

Simplified Programming Overview

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 multimeter’s configuration

from the preset conditions. The multimeter offers a variety of low-level

commands in the INPut, SENSe, CALCulate, and TRIGger

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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Chapter 4 Remote Interface Reference

Simplified Programming Overview

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 multimeter’s 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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Chapter 4 Remote Interface Reference

Simplified Programming Overview

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 multimeter’s 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 transfer the readings from the

multimeter’s internal memory to the multimeter’s 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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Chapter 4 Remote Interface Reference

Simplified Programming Overview

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 multimeter’s 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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Chapter 4 Remote Interface Reference

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 5¹⁄₂digits slow (10 PLC).

Note: You must specify a r a n ge to use the r esolu tion parameter.

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 6¹⁄₂digits. 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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The MEASure? and CONFigure Commands

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 6¹⁄₂digits. 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 kΩ range and 5¹⁄₂digits).

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 5¹⁄₂digits).

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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

6¹⁄₂digits. The resolution parameter only affects the front-panel display.

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

6¹⁄₂digits. 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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The MEASure? and CONFigure Commands

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 kΩ range and 5¹⁄₂digits).

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 5¹⁄₂digits).

CONFigure?

Query the multimeter’s present configuration and return a quoted string.

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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?

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 signal’s 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 (4¹⁄₂digits), 100 m s (default;

5¹⁄₂digits), or 1 second (6¹⁄₂digits). 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 (4¹⁄₂digits), 100 m s (default;

5¹⁄₂digits), or 1 second (6¹⁄₂digits). 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).

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 MΩ for all ranges. With AUTO ON, the input resistance is set to

>10 GΩ for 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

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.

Ω 2W

Ω 4W

DC V AC V DC I

AC I

Freq

Per

Cont

Diode Ratio

Null

Min-Max

dBm

Limit

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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Math Operation Commands

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]

CALCulate:NULL:OFFSet {<value>|MINimum|MAXimum}

Store a null value in the multimeter’s 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 Ω. MAX = 8000 Ω. [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 multimeter’s 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

See also “Triggering,” starting on page 71 in chapter 3.

First-time

SCPI users,

see page 154.

The multimeter’s 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.

•

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 multimeter’s 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

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

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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Chapter 4 Remote Interface Reference

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 multimeter’s 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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Triggering Commands

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).

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

See also “System-Related Operations,” starting on page 84 in chapter 3.

FETCh?

Transfer readings stored in the multimeter’s internal memory by the

INITiatecommand to the multimeter’s 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 multimeter’s 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.

SYSTem:VERSion?

Query the multimeter to determine the present SCPI version.

DATA:POINts?

Query the number of readings stored in the multimeter’s 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 multimeter’s identification string (be sure to dimension a

string variable with at least 35 characters).

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The SCPI Status Model

All SCPI instruments implement status registers in the same way.

The status system records various instrument conditions in three

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

*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

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

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Chapter 4 Remote Interface Reference

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 multimeter’s 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.

One or more bits are set in the Questionable Data

Data is available in the multimeter’s output buffer.

One or more bits are set in the Standard Event

The multimeter is requesting service (serial poll).

Always set to 0.

Value

0 Not Used

1 Not Used

2 Not Used

3 Questionable Data

4 Message Available

5 Standard Event

6 Request Service

7 Not Used

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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Chapter 4 Remote Interface Reference

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

the status byte summary register. No other bits are affected. Performing

a serial poll will not affect instrument throughput.

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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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

•

Send the *OPC?(operation complete query) command and enter the

result to assure synchronization.

Enable your bus controller’s 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 multimeter’s 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 multimeter’s internal memory when using INITiate.

Sending the FETCh?command transfers readings (stored in internal

memory by the INITiatecommand) to the multimeter’s output buffer.

Therefore, the MAV bit can only be set after all measurements have

been completed.

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 multimeter’s 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 multimeter’s 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

However, no error message is recorded in the multimeter’s error queue.

Bit Definitions – Standard Event Register

Decimal

Bit

Definition

Value

0 Operation Complete

All commands prior to and including an *OPC

command have been executed.

1 Not Used

2 Query Error

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

4 Execution Error

5 Command Error

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

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.

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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 multimeter’s 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

multimeter’s 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 Current Overload

2 Not Used

3 Not Used

Always set to 0.

4 Not Used

Always set to 0.

5 Not Used

Always set to 0.

6 Not Used

Always set to 0.

7 Not Used

8 Not Used

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.

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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.

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Status Reporting Commands

SYSTem:ERRor?

Query the multimeter’s 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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*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

*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

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]

*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

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: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

procedure.

CALibration:VALue?

Query the present calibration value.

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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 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

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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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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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 multimeter’s 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.

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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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

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.

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

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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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.

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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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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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"

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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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>

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>

Negative sign or positive sign

Numeric digits

Exponent

<nl> newline character

<cr> carriage return character

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Chapter 4 Remote Interface Reference

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 multimeter’s 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 multimeter’s 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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Chapter 4 Remote Interface Reference

To Set the GPIB Address

Each device on the GPIB (IEEE-488) interface must have a unique

address. You can set the multimeter’s 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.

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

∨

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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Chapter 4 Remote Interface Reference

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

∨

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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Chapter 4 Remote Interface Reference

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

∨

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

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.

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Chapter 4 Remote Interface Reference

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

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.

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Chapter 4 Remote Interface Reference

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

∨

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

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.

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Chapter 4 Remote Interface Reference

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:

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

Perform a calibration.

Perform a self-test and reset.

Command is accepted but is ignored.

Self-test is not executed.

Device Clear

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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”

PUT variable calibration value.

PUT user-defined message.

Perform self-test.

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.

Store input as calibration value.

Begin A/D calibration.

Begin high-frequency AC calibration.

Enter ERASE mode.

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Chapter 4 Remote Interface Reference

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?

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Chapter 4 Remote Interface Reference

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?

*CLS

*ESE <enable value>

*ESE?

*STB?

*ESR?

*TRG

*IDN?

*TST?

*OPC

*OPC?

*PSC {0|1}

*PSC?

169

170

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"

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Chapter 5 Error Messages

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

-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.

Tr igger d ea d lock

A trigger deadlock occurs when the trigger source is BUS and a READ?

command is received.

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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 multimeter’s 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?

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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

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

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.

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 MΩ range.

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

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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

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 interface’s 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

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$)

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

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 multimeter’s 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

Print A(I);

Next I

END

187

Chapter 6 Application Programs

Using the Status Registers

The following example shows how you can use the multimeter’s 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

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

191

Chapter 6 Application Programs

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

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

#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 */

/* 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

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

Beryllium Copper

Aluminum

Kovar or Alloy 42

Silicon

Copper-Oxide

Cadmium-Tin Solder

Tin-Lead Solder

500

1000

0.2

The Agilent 34401A’s 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 multimeter’s own

input resistance. The diagram below shows this error source.

R_s

V = ideal DUT voltage

R = DUT source resistance

R = multimeter input resistance

Ideal

Meter

V_s

R_i

( 10 MΩ or >10 GΩ )

100 x R_s

Error (%) =

R_s+ R_i

To reduce the effects of loading errors, and to minimize noise pickup,

you can set the multimeter’s input resistance to greater than 10 GΩ for

the 100 mVdc, 1 Vdc, and 10 Vdc ranges. The input resistance is

maintained at 10 MΩ for the 100 Vdc and 1000 Vdc ranges.

Lea k a ge Cu r r en t Er r or s

The multimeter’s input capacitance will “charge up” due to input bias

currents when the terminals are open-circuited (if the input resistance

is 10 GΩ). The multimeter’s 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 kΩ, or when the

multimeter’s operating temperature is significantly greater than 30°C.

i = multimeter bias current

R = DUT source resistance

C = multimeter input capacitance

For DCV ranges:

0.1V, 1V, 10V: C < 700 pF

100V, 1000V: C < 50 pF

Ideal

Meter

i_b

C_i

For all ACV ranges: < 50 pF

Error (v) ≅ i x R

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)

4¹⁄₂Fast

4¹⁄₂Slow

5¹⁄₂Fast

5¹⁄₂Slow

6¹⁄₂Fast

6¹⁄₂Slow

0.02

0.2

100

400 µs

16.7 ms (20 ms)

3 ms (3 ms)

167 ms (200 ms)

1.67 sec (2 sec)

(400 µs)

–

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 multimeter’s input LO

terminal and earth ground as shown below. This can cause errors when

measuring low voltages which are floating relative to earth ground.

V = float voltage

R = DUT source resistance

imbalance

R = multimeter isolation

Ideal

Meter

V_test

R_s

resistance (LO-Earth)

C = multimeter input

capacitance:

≈200 pF (LO-Earth)

V_f

C_i

R_i>10 GΩ

V_fx R_s

Error ( v ) =

R_s+ R_i

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.

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 multimeter’s

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.

R_L

Ideal

Meter

V_test

R_L

R_i>10 GΩ

V_ground

R_L= lead resistance

R_i= 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-Sense

V_meter

Ideal

Meter

R =

test

I _test

LO-Sense

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 multimeter’s

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

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 kΩ. 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 (10⁹ohms) when compared to PTFE

ꢀ

Teflon insulators (10 ohms). Leakage from nylon or PVC insulators

can easily contribute a 0.1% error when measuring a 1 MΩ resistance 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 multimeter’s series burden voltage. A voltage is developed

across the wiring resistance and current shunt resistance of the

multimeter as shown below.

R_s

Ideal

Meter

V_b

V_s

= source voltage

= DUT source resistance

= multimeter burden voltage

= multimeter current shunt

−100% x V_b

Error ( % ) =

V_s

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 multimeter’s 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.

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

– 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 multimeter’s 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 MΩ resistance 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 multimeter’s

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 R_s

Error (%) =

R_s+ 1 MΩ

Additional error for high frequencies:

Error (%) = 100 x

− 1

1 + ( 2 π x F x R_sx C_in)²

√

R_s= source resistance

F = input frequency

C_in= input capacitance (100 pF) plus cable capacitance

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

multimeter’s internal signal-conditioning components. These errors are

included in the multimeter’s 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 multimeter’s 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 multimeter’s 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.

Voltage Measured =

V_in+ 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.

211

Chapter 7 Measurement Tutorial

Common Mode Errors

Com m on Mod e Er r or s

Errors are generated when the multimeter’s 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 source’s response to this

loading. The multimeter’s measurement circuitry, while extensively

shielded, responds differently in the backward input case due to slight

differences in stray capacitance to earth. The multimeter’s 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 multimeter’s 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 multimeter’s 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 multimeter’s 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 multimeter’s 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.

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 multimeter’s 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 multimeter’s 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

Specifications

Chapter 8 Specifications

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

0.0040 + 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

Resistance

[ 4 ]

100.0000 Ω

1 mA

100 µA

10 µA

5 µA

0.0030 + 0.0030

0.0020 + 0.0005

0.002 + 0.001

0.008 + 0.004

0.008 + 0.001

0.020 + 0.001

0.800 + 0.010

0.010 + 0.004

0.010 + 0.001

0.040 + 0.001

0.800 + 0.010

0.0006 + 0.0005

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

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

Diode Test

[12]

1.0000 V

DC:DC Ratio

100 mV

( 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.

Using 6¹⁄₂digit 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

6¹⁄₂

5¹⁄₂

4¹⁄₂

0.6 (0.5)

6 (5)

60 (50)

300

0% 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]

Selectable 10 MΩ or >10 GΩ [11]

10 MΩ ±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

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 Ω, 1 kΩ

ranges. 1 kΩ per 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:

0.1Ω for 1A, 3A. 5Ω for 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 Ω 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 6¹⁄₂digits.

[ 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 kΩ unbalance 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 ]

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 4¹⁄₂digits, 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 mΩ for resistance.

[ 11 ] For these ranges, inputs beyond ±17V are

clamped through 100 kΩ (typical).

Teflon is a registered trademark of E.I. duPont deNemours and Co.

217

Chapter 8 Specifications

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

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

Fast

––

0.73

0.22

0.18

10 Hz – 20 Hz

20 Hz – 40 Hz

40 Hz – 100 Hz

100 Hz – 200 Hz

200 Hz – 1 kHz

> 1 kHz

2 – 3

3 – 4

4 – 5

0.15%

0.30%

0.40%

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 6¹⁄₂digit 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

Reading/s

7 sec/reading

Digits

6¹⁄₂

Measurement Noise Rejection [ 8 ]

AC CMRR

70 dB

6¹⁄₂

1.6 [ 10 ]

50 [ 11 ]

True RMS AC Voltage

6¹⁄₂

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

6¹⁄₂

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

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 Ω for 1 A and 3 A ranges

1 A range: < 1 V rms

[ 1 ] Specifications are for 1-hour warm-up at 6¹⁄₂digits,

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 8x10⁷Volt-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 kΩ unbalance 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 4¹⁄₂digits, Delay 0, Display OFF, and

Fast AC filter.

219

Chapter 8 Specifications

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

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

0.001

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

6¹⁄₂

5¹⁄₂

0.12

0.17

0.2

4¹⁄₂

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

0.06

0.03

0.01

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 6¹⁄₂digit 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

6¹⁄₂

Frequency and Period

Measurement Method:

9.8

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.

5¹⁄₂

4¹⁄₂

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

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 6¹⁄₂digits.

[ 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 4¹⁄₂digits, Delay 0, Display OFF,

and Fast AC filter.

221

Chapter 8 Specifications

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

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.

223

Chapter 8 Specifications

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 multimeter’s specifications.

The multimeter’s 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 multimeter’s 24-hour dc voltage specification.

Reading Error

(% of reading)

Reading

Error Voltage

Range

Input Level

10 Vdc

1 Vdc

0.1 Vdc

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 multimeter’s 24-hour dc voltage specification.

Range Error

(% of range)

Range

Error Voltage

Range

Input Level

10 Vdc

1 Vdc

0.1 Vdc

0.0004

≤ 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

225

Chapter 8 Specifications

Interpreting Multimeter Specifications

This section is provided to give you a better understanding of the terminology

used and will help you interpret the multimeter’s 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 “9’s” the

multimeter can measure or display. This indicates the number of full

digits. Most multimeters have the ability to overrange and add a partial

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 6¹⁄₂-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 6¹⁄₂-digit multimeter if it has a 1 Vdc or smaller range.

You could also use a 4¹⁄₂-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 6¹⁄₂-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 multimeter’s

measurement uncertainty can be determined relative to the calibration

reference used. Absolute accuracy includes the multimeter’s 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.

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 multimeter’s 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 multimeter’s 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

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 GΩ (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.

•

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.

“¹⁄₂” 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

See four-wire ohms

“9.90000000E+37”, 61, 131

bandwidth detector, 51, 214

bandwidth error, 208

baud rate, 93, 148, 151, 163

beeper

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

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

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

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

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)

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

“half” digit, 21, 54

hardware lines (IEEE-488), 169

handle

internal triggering, 75

adjusting, 16

removing, 23

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

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

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

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

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

questionable data register

bit definitions, 142

clearing, 143

parameter types, 158

parity, 93, 164

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

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

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

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

“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

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

zero measurements, 59, 213

236

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