Contents
HP E8491A IEEE 1394 PC Link to VXI Configuration and User’s Guide
Edition 1
Safety Symbols ............................................................................................................. 6
WARNINGS................................................................................................................. 6
Declaration of Conformity............................................................................................ 7
Reader Comment Sheet ................................................................................................ 9
Chapter 1
Introduction .................................................................................................................. 11
Using the IEEE 1394 Serial Bus in VXI Systems ...................................................... 11
Component Overview ......................................................................................... 11
The HP I_O Libraries ................................................................................... 11
Using this Manual .............................................................................................. 11
Appendix A: Specifications .......................................................................... 12
Additional Information ........................................................................................ 12
Chapter 2
Interface Installation and Configuration ................................................................... 13
Using this Chapter ...................................................................................................... 13
Step 1: Installing the IEEE 1394Host Adapter .................................................... 13
Where to go Next .......................................................................................... 17
Alternate Configurations .............................................................................. 19
Where to go Next .......................................................................................... 20
Step 3: Installing VXI Instruments ...................................................................... 20
Installing C-size Instruments ........................................................................ 20
Installing A- and B-size Instruments ............................................................ 22
Step 4: Installing the HP I_O Libraries ............................................................... 24
Step 6. Verifying the Installation ........................................................................ 29
Using Instrument Soft Front Panels .............................................................. 29
Running the Resource Manager .......................................................................... 33
Contents
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Appendix B
Editing the HP E8491A Resource Manager Configuration ..................................... 69
Introduction................................................................................................................. 69
Configuration File Overview .............................................................................. 69
The names.cf Configuration File .................................................................. 72
The oride.cf Configuration File .................................................................... 72
The vmedev.cf Configuration File ................................................................ 72
The cmdrsrvt.cf Configuration File .............................................................. 72
The dynamic.cf Configuration File ............................................................... 72
The irq.cf Configuration File ........................................................................ 73
The ttltrig.cf Configuration File ................................................................... 73
Utility Function Overview .................................................................................. 73
Using ivxisc .................................................................................................. 73
Using iclear ................................................................................................... 75
Index ................................................................................................................................ 77
Contents
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Contents
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HEWLETT-PACKARD WARRANTY STATEMENT
HP PRODUCT: HP E8491A I E E E 1394 PC LINK to VXI DURATION OF WARRANTY:
3 years
1. HP warrants HP hardware, accessories and supplies against defects in materials and workmanship for the period specified above. If
HP receives notice of such defects during the warranty period, HP will, at its option, either repair or replace products which prove to be
defective. Replacement products may be either new or like-new.
2. HP warrants that HP software will not fail to execute its programming instructions, for the period specified above, due to defects in
material and workmanship when properly installed and used. If HP receives notice of such defects during the warranty period, HP will
replace software media which does not execute its programming instructions due to such defects.
3. HP does not warrant that the operation of HP products will be interrupted or error free. If HP is unable, within a reasonable time, to
repair or replace any product to a condition as warranted, customer will be entitled to a refund of the purchase price upon prompt return
of the product.
4. HP products may contain remanufactured parts equivalent to new in performance or may have been subject to incidental use.
5. The warranty period begins on the date of delivery or on the date of installation if installed by HP. If customer schedules or delays HP
installation more than 30 days after delivery, warranty begins on the 31st day from delivery.
6. Warranty does not apply to defects resulting from (a) improper or inadequate maintenance or calibration, (b) software, interfacing, parts
or supplies not supplied by HP, (c) unauthorized modification or misuse, (d) operation outside of the published environmental
specifications for the product, or (e) improper site preparation or maintenance.
7. TO THE EXTENT ALLOWED BY LOCAL LAW, THE ABOVE WARRANTIES ARE EXCLUSIVE AND NO OTHER
WARRANTY OR CONDITION, WHETHER WRITTEN OR ORAL, IS EXPRESSED OR IMPLIED AND HP SPECIFICALLY
DISCLAIMS ANY IMPLIED WARRANTY OR CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, AND
FITNESS FOR A PARTICULAR PURPOSE.
8. HP will be liable for damage to tangible property per incident up to the greater of $300,000 or the actual amount paid for the product
that is the subject of the claim, and for damages for bodily injury or death, to the extent that all such damages are determined by a court
of competent jurisdiction to have been directly caused by a defective HP product.
9. TO THE EXTENT ALLOWED BY LOCAL LAW, THE REMEDIES IN THIS WARRANTY STATEMENT ARE CUSTOMER’S
SOLE AND EXLUSIVE REMEDIES. EXCEPT AS INDICATED ABOVE, IN NO EVENT WILL HP OR ITS SUPPLIERS BE
LIABLE FOR LOSS OF DATA OR FOR DIRECT, SPECIAL, INCIDENTAL, CONSEQUENTIAL (INCLUDING LOST PROFIT OR
DATA), OR OTHER DAMAGE, WHETHER BASED IN CONTRACT, TORT, OR OTHERWISE.
FOR CONSUMER TRANSACTIONS IN AUSTRALIA AND NEW ZEALAND: THE WARRANTY TERMS CONTAINED IN THIS
STATEMENT, EXCEPT TO THE EXTENT LAWFULLY PERMITTED, DO NOT EXCLUDE, RESTRICT OR MODIFY AND ARE
IN ADDITION TO THE MANDATORY STATUTORY RIGHTS APPLICABLE TO THE SALE OF THIS PRODUCT TO YOU.
U.S. Government Restricted Rights
The Software and Documentation have been developed entirely at private expense. They are delivered and licensed as "commercial
computer software" as defined in DFARS 252.227- 7013 (Oct 1988), DFARS 252.211-7015 (May 1991) or DFARS 252.227-7014 (Jun
1995), as a "commercial item" as defined in FAR 2.101(a), or as "Restricted computer software" as defined in FAR 52.227-19 (Jun
1987)(or any equivalent agency regulation or contract clause), whichever is applicable. You have only those rights provided for such
Software and Documentation by the applicable FAR or DFARS clause or the HP standard software agreement for the product involved.
HP E8491A IEEE 1394 PC Link to VXI Configuration and User’s Guide
Edition 1
Copyright © 1998 Hewlett-Packard Company. All Rights Reserved.
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Documentation History
All Editions and Updates of this manual and their creation date are listed below. The first Edition of the manual is Edition 1. The Edition
number increments by 1 whenever the manual is revised. Updates, which are issued between Editions, contain replacement pages to
correct or add additional information to the current Edition of the manual. Whenever a new Edition is created, it will contain all of the
Update information for the previous Edition. Each new Edition or Update also includes a revised copy of this documentation history page.
Edition 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .June 1998
Safety Symbols
Instruction manual symbol affixed to
Alternating current (AC)
product. Indicates that the user must refer to
the manual for specific WARNING or
CAUTION information to avoid personal
injury or damage to the product.
Direct current (DC).
Indicates hazardous voltages.
Indicates the field wiring terminal that must
be connected to earth ground before
operating the equipment—protects against
electrical shock in case of fault.
Calls attention to a procedure, practice, or
condition that could cause bodily injury or
death.
WARNING
CAUTION
Calls attention to a procedure, practice, or
condition that could possibly cause damage to
equipment or permanent loss of data.
Frame or chassis ground terminal—typically
connects to the equipment's metal frame.
or
WARNINGS
The following general safety precautions must be observed during all phases of operation, service, and repair of this product. Failure to
comply with these precautions or with specific warnings elsewhere in this manual violates safety standards of design, manufacture, and
intended use of the product. Hewlett-Packard Company assumes no liability for the customer's failure to comply with these requirements.
Ground the equipment: For Safety Class 1 equipment (equipment having a protective earth terminal), an uninterruptible safety earth
ground must be provided from the mains power source to the product input wiring terminals or supplied power cable.
DO NOT operate the product in an explosive atmosphere or in the presence of flammable gases or fumes.
For continued protection against fire, replace the line fuse(s) only with fuse(s) of the same voltage and current rating and type. DO NOT
use repaired fuses or short-circuited fuse holders.
Keep away from live circuits: Operating personnel must not remove equipment covers or shields. Procedures involving the removal of
covers or shields are for use by service-trained personnel only. Under certain conditions, dangerous voltages may exist even with the
equipment switched off. To avoid dangerous electrical shock, DO NOT perform procedures involving cover or shield removal unless you
are qualified to do so.
DO NOT operate damaged equipment: Whenever it is possible that the safety protection features built into this product have been
impaired, either through physical damage, excessive moisture, or any other reason, REMOVE POWER and do not use the product until
safe operation can be verified by service-trained personnel. If necessary, return the product to a Hewlett-Packard Sales and Service Office
for service and repair to ensure that safety features are maintained.
DO NOT service or adjust alone: Do not attempt internal service or adjustment unless another person, capable of rendering first aid and
resuscitation, is present.
DO NOT substitute parts or modify equipment: Because of the danger of introducing additional hazards, do not install substitute parts
or perform any unauthorized modification to the product. Return the product to a Hewlett-Packard Sales and Service Office for service
and repair to ensure that safety features are maintained.
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Declaration of Conformity
according to ISO/IEC Guide 22 and EN 45014
Manufacturer’s Name:
Hewlett-Packard Company
Loveland Manufacturing Center
Manufacturer’s Address:
815 14th Street S.W.
Loveland, Colorado 80537
declares, that the product:
Product Name:
Model Number:
Product Options:
IEEE 1394 PC Link to VXI
HP E8491A
All
conforms to the following Product Specifications:
Safety:
IEC 1010-1 (1990) Incl. Amend 1 (1992)/EN61010-1 (1993)
CSA C22.2 #1010.1 (1992)
UL 3111-1 (1994)
EMC:
CISPR 11:1990/EN55011 (1991): Group1 Class A
IEC 801-2:1991/EN50082-1 (1992): 4kVCD, 8kVAD
IEC 801-3:1984/EN50082-1 (1992): 3 V/m
IEC 801-4:1988/EN50082-1 (1992): 1kV Power Line
.5kV Signal Lines
Supplementary Information: The product herewith complies with the requirements of the Low Voltage Directive
73/23/EEC and the EMC Directive 89/336/EEC (inclusive 93/68/EEC) and carries the "CE" mark accordingly.
Tested in a typical configuration in an HP C-Size VXI mainframe.
Jim White, QA Manager
June, 1998
European contact: Your local Hewlett-Packard Sales and Service Office or Hewlett-Packard GmbH, Depart-
ment HQ-TRE, Herrenberger Straße 130, D-71034 Böblingen, Germany (FAX +49-7031-14-3143)
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Notes:
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Please fold and tape for mailing
Reader Comment Sheet
HP E8491A IEEE 1394 PC Link to VXI Configuration and User’s Guide
Edition 1
You can help us improve our manuals by sharing your comments and suggestions. In appreciation of your time, we will
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Please list the system controller, operating system, programming language, and plug-in modules you are using.
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Chapter 1
Introduction
Using the IEEE 1394 Serial Bus in VXI Systems
The IEEE 1394 Serial Bus (FireWire) is a high-speed bus that has been
implemented as an I/O interface between external PCs and HP VXI systems.
The bus links the PC backplane to the VXI mainframe backplane. This
manual describes the implementation, configuration, and use of this
interface.
Component Implementation of the IEEE 1394 serial bus as an I/O interface for HP VXI
systems is provided through three components:
Overview
• HP E8491A PC Link to VXI Interconnect
®
• Adaptec AHA-8940 1394-to-PCI Host Adapter
• HP I_O Libraries
The HP E8491A PC Link The HP E8491A is the VXI hardware that links the VXI mainframe
backplane to the IEEE 1394 serial bus. The E8491A is a 1-slot, C-size,
message-based device that is installed in mainframe slot 0.
to VXI Interconnect
The Adaptec® AHA-8940 The Adaptec® AHA-8940 1394-to-PCI Host Adapter card is installed in the
PC and links the computer’s (PCI) backplane to the IEEE 1394 bus. The
AHA-8940 has one internal and two external IEEE 1394 ports and can
support up to 16 HP E8491As.
1394-to-PCI Host Adapter
The HP I_O Libraries The HP I_O Libraries provide the HP VISA and HP SICL drivers required
to use the HP E8491A. Included with the libraries are the drivers for the
®
Adaptec AHA-8940 host adapter.
Using this Manual This manual is organized to help you install, configure, and begin using the
IEEE 1394 serial bus as quickly and efficiently as possible. The following
information outlines the contents of the other chapters, and identifies the
areas of programming a VXI system that are NOT covered in this manual.
Chapter 2: Interface This chapter contains information on installing the HP E8491A hardware
and its drivers (the HP I_O Libraries). Also included is information on
installing VXI instruments, installing HP VXIplug&play drivers, and on
verifying the system.
Installation and
Configuration
Introduction
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Chapter 3: VXI This chapter contains the information necessary to begin communicating
with VXI instruments through the HP E8491A and IEEE 1394 serial bus.
The chapter contains information on optimizing system performance using
block data transfers, and also covers triggering and using HP E8491A shared
memory.
Programming Using the
IEEE 1394 Serial Bus
Chapter 4: IEEE 1394 This chapter describes the IEEE 1394 serial bus and how it is implemented
in HP VXI systems. It defines the bus terminology and data transfer
protocol.
Fundamentals and
Interface Overview
Appendix A: Appendix A contains the operating and performance specifications of the
HP E8491A.
Specifications
Appendix B: Editing the Appendix B contains information on editing your VXI system configuration
as set by the resource manager. It describes selected configuration files and
utility functions used to view and modify your configuration.
HP E8491A Resource
Manager Configuration
Additional Programming the HP E8491A is through HP VISA and HP SICL functions.
Although this manual identifies the specific functions used, you will need to
Information
refer to the HP VISA and HP SICL manuals for detailed information.
Also, included with the HP I_O Libraries is the utility ‘I_O Config’. This
utility is used to configure the HP E8491A and has a help file associated with
it.
12 Introduction
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Chapter 2
Interface Installation and Configuration
Using this Chapter
This chapter contains information necessary to install and configure the
IEEE 1394 host adapter (if required) and the HP E8491A interconnect. The
installation sequence and other topics covered in this chapter are as follows:
Step 1: Installing The IEEE 1394 adapter shipped as Option 001 to the HP E8491A is the
®
Adaptec AHA-8940 1394-to-PCI Host Adapter. Included with the adapter
the IEEE 1394
Host Adapter
is a cable for powering 1394 devices and a 4.5m interface cable.
®
Note If your personal computer (PC) currently has an Adaptec IEEE-1394 host
adapter or built-in IEEE-1394 port, proceed to Step 2: Installing the HP
E8491 Interconnect.
®
The layout of the Adaptec host adapter is shown in Figure 2-1.
Interface Installation and Configuration
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12 VDC power connector
Internal IEEE 1394 connector
External
IEEE 1394
connectors
Figure 2-1. Layout of the Adaptec® AHA-8940 1394-to-PCI Host Adapter.
WARNING Turn off and disconnect the power to your computer and to any
peripheral devices before installing the host adapter.
A. Remove the computer chassis cover to expose the expansion slots and
external access covers.
B. Locate an unused, unobstructed PCI bus expansion slot (Figure 2-2)
that supports bus mastering. (PCI bus slots are usually white or
ivory.) See your computer documentation to determine if the PCI slot
supports bus mastering.
14 Interface Installation and Configuration
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PCI expansion slots
(usually white or ivory)
shared slot
Figure 2-2. Locating a PCI bus Expansion Slot.
Note Many computer PCI systems have one pair of ISA and PCI slots close to
each other. This saves space and allows you to install either an ISA card or
a PCI card in the slot pair.
C. Remove the corresponding expansion slot cover from the computer
chassis (Figure 2-3).
expansion slot cover
Figure 2-3. Removing the PC Expansion Slot Cover.
Interface Installation and Configuration
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D. Align the bus contacts on the bottom of the host adapter with the PCI
bus slot. Carefully, but firmly, press the adapter into the slot.
host adapter
Figure 2-4. Installing the Host Adapter.
E. Secure the host adapter bracket to the computer chassis with the
screw from the expansion slot cover removed in step C.
Connecting the Power Cable
F. Connect the power cable between the adapter and the PC as shown in
Figure 2-5. This provides power from the adapter to devices along the
interface via the interface cable. This allows you to cycle power on
any VXI mainframe in multi-frame systems without affecting other
frames. The power is also available to other IEEE 1394 devices that
®
may be part of the interface network. The Adaptec host adapter is
capable of supplying 12V with a maximum current draw of 1.5 amps.
16 Interface Installation and Configuration
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power in
(from system power supply)
power out
(to disk drives)
host adapter
12V DC power connector
Figure 2-5. Connecting the Power Cable Between the PC and the Host Adapter.
G. Replace the computer cover. Connect one end of the interface cable to
either of the adapter’s external connectors. You can now turn on the
PC.
Note When power is applied, Windows 95 operating systems may detect the
®
Adaptec card and indicate that it cannot locate an associated .inf file.
Ignore this message as the .inf file is installed when the HP I_O Libraries
are installed (Step 4).
Note Refer to Chapter 4: IEEE 1394 Fundamentals and Interface Overview for
®
more information on the Adaptec host adapter.
Where to go Next If you are installing the IEEE 1394 interface for the first time, continue with
“Step 2: Installing the HP E8491A Interconnect.” If the E8491A and your
VXI instruments are already installed, proceed to “Step 4: Installing the
®
HP I_O Libraries.” Notice that the HP I_O Libraries contain the Adaptec
host adapter drivers.
Step 2: Installing The HP E8491A interconnect links the IEEE 1394 bus to the backplane of
the VXI mainframe. The E8491A is a C-size device with VXI Resource
Manager and Slot 0 capability.
the HP E8491A
Interconnect
There are no configuration switches on the E8491A. The device’s logical
address is 0 and it provides the system’s resource manager functionality via
software that is part of the HP I_O Libraries. Its VXI servant area is 255,
therefore; it is the interface to all VXI devices with logical addresses
between 1 and 255. The E8491A is normally, but not required to be,
installed in mainframe slot 0.
Interface Installation and Configuration
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Note Refer to “Alternate Configurations” for information on using the E8491A
with the HP E1406 Command Module and using it in VXI-MXI systems.
A. If turned on, turn off the VXI mainframe and disconnect all power
sources that may be applied to any instruments.
B. Insert the E8491A into mainframe slot 0 by aligning the module with
the guides inside the mainframe (Figure 2-6). Slowly push the module
into the slot until it seats in the backplane connectors. It may be
necessary to pull out (not remove) the retaining screws in order to
seat the device securely in the connectors.
seat the module by
pushing in the
extraction levers
extraction
levers
retaining
screws
slide the module
into the mainframe
until it plugs into the
backplane connectors
Figure 2-6. Installing the HP E8491A in the VXI Mainframe.
18 Interface Installation and Configuration
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C. Tighten the retaining screws on the top and bottom of the module.
Connecting the HP E8491A to the Host Adapter
D. Connect the interface cable from the host adapter to E8491A port A,
B, or C. The ports are identical and unused ports are available to
connect additional E8491As and other IEEE 1394 devices in a
daisy-chain or tree configuration (Figure 2-7). Notice that there can
be no closed loops.
DAISY-CHAIN CONFIGURATION
TREE CONFIGURATION
PC
PC
VXI
VXI
VXI
VXI
VXI
VXI
VXI
*
*
A second connection creates a closed loop and is not allowed
Figure 2-7. IEEE 1394 Interface Configurations.
I/O performance is impacted slightly by the hardware configuration.The
VXI mainframe with the fewest number of hops (cable links) to the PC has
the highest priority. However, each mainframe has equal access to the bus
during each data transfer interval.
Note Refer to Chapter 4: IEEE 1394 Fundamentals and Interface Overview for
information on the topology and terms associated with the IEEE 1394 bus.
Alternate Configurations Certain applications may include the HP E1406A Command Module as an
HP-IB interface to selected instruments. In this configuration, the E8491A
must be the resource manager since its logical address is always 0. It is
generally installed in mainframe slot 0 so that it also provides the system’s
slot 0 functionality.
Interface Installation and Configuration
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If you want the E1406 to provide slot 0 functionality in addition to providing
an HP-IB interface, set its configuration as follows:
1. Set the E1406 logical address to a value other than 0.
2. Set the Slot 0 and System Controller switches to “Enable” (default).
3. Set the CLK 10 source to “Internal” (default).
4. Set the VME BTO Disable switch to 0 - Enable (default). Set VME
Bus Timeout (BTO) on the E8491A to ‘Off’ (see “Editing the
HP E8491A Configuration” later in this chapter).
5. Set the E1406 servant area to include the logical addresses of those
instruments it is to control. Note:
E1406 servant area = (E1406 logical address + 1) through
(E1406 logical address + servant area switch setting)
6. Install the E1406 in slot 0.
If the E1406 is not the slot 0 device, its slot 0 functionality must be disabled.
From step 2 above, set the E1406A Slot 0 and System Controller switches
to “Disable”. From step 4, set its VME BTO Disable switch 1 and ensure that
VME Bus Timeout (BTO) on the E8491A is set to ‘On’.
If you are using the E8491A in a configuration with multiple mainframes
linked with MXI extender cards, the E8491A must be the resource manager;
however, VME Bus Timeout (BTO) must be disabled (off - Step 4 above).
Again, the E8491A is generally installed in mainframe slot 0 so that it also
provides the system’s slot 0 functionality. Refer to the MXI documentation
for configuration guidelines based on where the E8491A is installed.
Where to go Next If you are installing the IEEE 1394 interface and your VXI system for the
first time, continue with “Step 3: Installing VXI Instruments.” If your VXI
instruments are already installed, proceed to “Step 4: Installing the HP I_O
Libraries.”
Step 3: Installing Generally, any VXI instrument can be installed in any slot other than slot 0.
VXI Instruments
When installing instruments, notice that the E8491A and the IEEE 1394 bus
do not extend the (VXI) backplane between frames in multi-frame VXI
systems (MXI cards are required). This means that the multimeter and
multiplexers in a VXI scanning multimeter for example, must be installed in
the same mainframe (in adjacent slots). Devices sharing the VXI Local bus
must also be installed in the same mainframe.
Installing C-size Figure 2-8 shows the installation of C-size instruments.
Instruments
20 Interface Installation and Configuration
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seat the module by
pushing in the
extraction levers
retaining
screws
extraction
levers
slide the module
into the mainframe
until it plugs into the
backplane connectors
Figure 2-8. Installing C-size Instruments.
Caution To prevent damage to the VXI instruments, install the
instruments when the mainframe is turned off.
A. Insert the instrument into the mainframe by aligning the instrument
with the card guides inside the mainframe. Slowly push the
instrument into the slot until it seats in the backplane connectors. The
front panel of the instrument should be even with the front edges of
the mainframe.
B. Tighten the retaining screws on the top and bottom of the module.
Interface Installation and Configuration
21
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WARNING All instruments within the VXI mainframe are grounded through
the mainframe chassis. During installation, tighten the
instruments’ retaining screws to secure the instrument to the
mainframe and to make the ground connection.
Installing A- and B-size A- and B-size instruments can also be installed in the mainframe. These
instruments are installed using a module carrier:
Instruments
• HP E1403C A/B-size Module Carrier extends the P1 connector on
the VXIbus backplane and mounts the (A/B-size) modules flush with
C-size modules. This carrier is recommended for Hewlett-Packard
B-size, slave-only devices which have the P1 connector.
• HP E1407A A/B Module Carrier extends the P1and P2 connectors
on the VXIbus backplane. This carrier is recommended for B-size,
slave-only devices which have the P1/P2 connectors.
Figure 2-9 shows the installation of A- and B-size instruments.
22 Interface Installation and Configuration
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Figure 2-9. Installing A- and B-size VXI Instruments.
Interface Installation and Configuration
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Caution To prevent damage to the VXI instruments, install the
instruments when the mainframe is turned off.
A. Install the HP E1403 A/B-size Module Carrier or the HP E1407
A/B-size Module Carrier into the mainframe. This is done by
aligning the top and bottom of the carrier with the card guides and
slowly pushing the carrier into the mainframe. The front of the
carrier should be even with the front edges of the mainframe.
B. Slide the A- or B-size instrument into the carrier until it connects.
C. Tighten the retaining screws on the top and bottom of the instrument.
WARNING All instruments within the VXI mainframe are grounded through
the mainframe chassis. During installation, tighten the
instruments’ retaining screws to secure the instrument to the
mainframe and to make the ground connection.
Step 4: Installing The software required to use the IEEE 1394 interface in a VXI system,
®
including the Adaptec host adapter drivers, is contained on the HP I_O
the HP I_O Libraries
Libraries CD.
Note Refer to Chapter 4: IEEE 1394 Fundamentals and Interface Overview for
more information on the HP I_O Libraries and related software.
A. Turn on the PC if you have not already done so. Close all open
applications and insert the I_O libraries CD into your PC CD-ROM
drive. Inserting the CD automatically activates the installer. If the
installer is not activated, select Start / Run and type
<drive>:SETUP.EXE. Do not turn on the VXI mainframe.
Note If your PC indicates that new hardware has been found, select “do not
®
install a driver.” The Adaptec host adapter drivers are installed with the
I_O libraries installer program.
B. Review the information and license agreements presented at the
beginning of the installation process.
C. Continue through the installation process as directed by the installer.
Be sure to indicate that you want HP I_O Libraries support for the
E8491A interface installed by clicking on the box next to “Install
HP E8491 VXI Components.” Do not configure the interface at this
time.
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D. After the installation is complete, re-start the computer.
Configuring the
HP E8491A Interconnect
A. Connect the IEEE 1394 interface cable between the host adapter (PC)
and the E8491A interconnect if you have not already done so. Turn
on the VXI mainframe.
B. From the HP I_O Libraries program group created when the libraries
were installed, click on ‘I_O Config’ (Figure 2-10).
Figure 2-10. The HP I_O Libraries Program Group.
This brings up a configuration window similar to that shown in
Figure 2-11.
C. Select HP E8491Ain the “Available Interface Types” box and click
on ‘Configure’
Interface Installation and Configuration
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.
interface name
interface number
Figure 2-11. The HP I_O Libraries I_O Config Utility.
The HP E8491A uses the SICL interface name ‘vxi’ and the VISA
interface name ‘VXI’ (Figure 2-12). The VISA interface number is
assigned by ‘I_O Config’ and is unique to each E8491A. The interface
name and number identify each mainframe in multi-frame VXI
systems, and are also used in addressing each instrument in the
mainframe. The unique interface number allows instruments with the
same logical addresses to be installed in different mainframes, but in
the same system.
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Figure 2-12. Editing the HP E8491A Configuration.
D. Click on OK to close the utility and complete the configuration.
Editing the HP E8491A When it is necessary to edit your configuration, click ‘I_O Config’ in the
HP I_O Libraries program group (Figure 2-10). To edit the HP E8491A,
click (highlight) the configured interface (vxi VXI0) in the utility (Figure
2-11). This activates the ‘Edit’ button on the bottom of the window.
Configuration
If you want to change the SICL interface name and number to something
more descriptive, use the ‘SICL Interface Name’ field. You can change the
VISA interface number using the up/down arrows next to the ‘VISA
Interface Name’ field. The SICL and VISA interface names (and numbers)
do not have to be the same.
Make a note of the interface name and number, as they are used in
addressing instruments in the mainframe (see “Chapter 3: VXI
Programming Using the IEEE 1394 Serial Bus” for more information).
The ‘Help’ button provides information on each item in the window.
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Editing the HP E8491A After installing the HP I_O Libraries and configuring the HP E8491A on the
Windows 95 platform, an hp icon is placed in the bottom right corner of your
PC monitor (Figure 2-13).
Configuration on
Windows 95 Platforms
Figure 2-13. Editing Your Configuration on Windows 95 Platforms.
Clicking on the icon using the right mouse button brings up the following
menu items:
I_O Config: starts the HP I_O Libraries’ ‘I_O Config’ utility.
Edit Resource Manager: goes directly to the Resource Manager section
of the ‘I_O Config’ utility (see Figure 2-16). This section allows you
to edit configuration files, run the resource manager on a specific
mainframe, and view the resource manager output. You must re-run
the resource manager each time changes are made.
Refresh Resource Manager: re-runs the resource manager on all VXI
mainframes in your system to implement configuration changes made.
You must “refresh” (re-run) the resource manager each time changes
are made. If changes are made to only a single configuration
(mainframe), see “Edit Resource Manager” above.
Close Application: stops the SICL iproc utility which enables the
resource manager to run. To re-start iproc, select
Start/Programs/StartUp/HP E8491 Resource Manager .
Step 5: Installing There are no SCPI instrument drivers installed in, or downloaded to the
HP E8491A. While this does not impact message-based instruments,
register-based instruments in IEEE 1394 based systems are programmed
the
HP VXIplug&play using their VXIplug&play drivers.
Instrument Drivers
The HP VXIplug&play drivers are located on the HP Universal Instrument
Drivers CD which ships with the E8491A and with each VXI
instrument.The installer program on the driver CD is similar to that on the
I_O libraries CD.
Once the drivers have been installed, reboot the PC.
28 Interface Installation and Configuration
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Note If you are updating an existing VXI system to use the HP E8491A and
IEEE 1394 serial bus, we highly recommend that you obtain the latest
version of the HP VXIplug&play drivers. Information on the latest drivers
available can be found on the World Wide Web at
Step 6. Verifying the Once you have installed the hardware, the I_O Libraries, the VXIplug&play
drivers, and have re-booted the PC, you should now verify the installation.
This ensures that you can communicate with instruments in the system over
Installation
the IEEE 1394 interface. Two ways to check your system are to run an
instrument’s soft front panel, or to view the output of the system’s resource
manager.
Using Instrument Soft Soft front panels are part of the instruments’ VXIplug&play drivers. A soft
front panel is activated from the ‘Vxipnp’ program group as shown in Figure
2-14.
Front Panels
Click to activate a soft
front panel
Figure 2-14. Selecting a VXIplug&play Soft Front Panel.
When the system hardware and software are properly installed and the PC is
communicating with the mainframe, the soft front panel will be opened and
a connection made to the instrument as shown in Figure 2-15.
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Green ‘Active’ indicator
shows communication to
instrument
Correct interface name and
logical address shown.
Figure 2-15. Soft Front Panel Indicating PC - Mainframe Communication.
Viewing the Resource Another way to determine if your system is properly configured is to view
the output of the resource manager. The easiest way to view the output is
Manager Output
using the I_O Libraries’ ‘I_O Config’ utility. Select and start the utility as
shown in Figures 2-10 through 2-12. The output is viewed as shown in
Figure 2-16.
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Select Enable Advanced to activate the Advanced
Settings controls. Click Resource Manager to bring
up the window below.
Click RM Output to view the
resource manager output.
Figure 2-16. Viewing the Resource Manager Output using ‘I_O Config’.
Figure 2-17 is a partial listing of a typical resource manager output.
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Figure 2-17. Typical Resource Manager Output.
32 Interface Installation and Configuration
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Running the When the VXI mainframe is turned on and the E8491A interface has been
configured using ‘I_O Config’, the SICL iproc utility is started. This enables
Resource Manager
the resource manager to run when:
• mainframe power is cycled
• the E8491A faceplate Reset button is pressed
• activated from the ‘I_O Config’ utility
The resource manager initializes and prepares the VXI system for use.
In VXI systems with multiple E8491As (mainframes), individual
mainframes can be turned off without affecting other mainframes in the
system. When a mainframe is turned on, the resource manager reconfigures
the mainframe.
Notice that the resource manager will only run if the iproc utility is started.
Again, configuring the E8491A interface using and then closing ‘I_O
Config’ starts iproc. You can manually start, stop, or verify the state of the
utility as shown in Figure 2-18.
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1. Click Start, select Set-
tings, and click Control
Panel.
2. Double-click
Services.
3. Select HP E8491
Resource Manager
and either Start, Stop,
or Close after verify-
ing.
Figure 2-18. Starting, Stopping, and Verifying iproc.
34 Interface Installation and Configuration
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Chapter 3
VXI Programming Using the IEEE 1394
Serial Bus
Using this Chapter
This chapter contains examples and general information for programming
VXI systems over the IEEE 1394 serial bus. The contents of the chapter
include:
• Programming Register-Based and Message-Based
Programming There are no SCPI instrument drivers for register-based instruments
installed in, or downloaded to the HP E8491A. Therefore, register-based
instruments are programmed over the IEEE 1394 bus using either their
Register-Based and
Message-Based VXI VXIplug&play drivers, or through register-level peeks and pokes using
HP VISA or SICL.
Instruments
Message-based instruments are programmed using HP VXIplug&play
drivers, or using SCPI commands embedded in HP VISA or SICL function
calls.
VXIplug&play drivers for HP register-based and message-based
instruments are contained on the HP Universal Instrument Drivers CD
which ships with each HP VXI instrument.
Opening Instrument Programs which run over the IEEE 1394 interface begin by opening a
session between the VXI instrument and the driver or I_O library (VISA or
SICL). An address that includes the interface name and number (described
Sessions
in Chapter 2) and the instrument’s logical address is used in opening these
sessions.
Following are three segments that open sessions to an instrument in
HP VXIplug&play, HP VISA, and SICL programs.
HP VXIplug&play
ViSession vi;
// open device (VXIplug&play) session to the HP E1563
errStatus = hpe1563_init(“VXI0::24::INSTR”,VI_FALSE,
VI_FALSE, &vi);
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HP VISA
ViSession defaultRM, id;
//open device (VISA) session to the HP E1563
viOpenDefaultRM (&defaultRM);
viOpen (defaultRM, “VXI0::24::INSTR”,VI_NULL,VI_NULL,
&id);
SICL
INST id;
// open device (SICL) session to the HP E1563
id = iopen(“vxi,24”)
Or, to open an interface session to the HP E8491A:
INST id;
// open (SICL) session to the VXI interface
id = iopen(“vxi”)
The HP E8491A IEEE 1394 interconnect uses the interface name VXI (or
vxi). The interface number is assigned using the ‘I_O Config’ utility
(Chapter 2). In the examples above, the logical address of the HP E1563
digitizer is 24 and INSTR indicates a VISA instrument control resource.
Optimizing Programs that run over the IEEE 1394 serial bus are optimized by
transferring data between the PC and the instrument in blocks. The
following section identifies HP VISA and SICL functions that perform
Programs
block transfers.
Note Refer to “Chapter 4: IEEE 1394 Fundamentals and Interface Overview” for
detailed information on data transfers using the IEEE 1394 data transfer
protocol.
Block Data Transfers VXIplug&play drivers for selected instruments contain functions that
perform block transfers. You will need to consult the driver help file to
determine if the driver for a particular instrument supports block transfers.
The following HP VISA functions perform block transfers over the
IEEE 1394 serial bus:
viMoveIn8
viMoveIn16
viMoveIn32
viMoveOut8
viMoveOut16
viMoveOut32
viMove
viMoveAsync
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The following extended SICL function is unique to the HP E8491A and is
used for block transfers over the bus:
iblockmovex
Additionally, the extended SICL functions shown below must be used when
porting SICL programs to the IEEE 1394 bus from other I/O interfaces:
imapx
iunmapx
ipeekx8, ipeekx16, ipeekx32
ipokex8, ipokex16, ipokex32
These functions are covered in detail in the SICL documentation.
The following examples demonstrate how to set up and perform block
transfers using HP VXIplug&play and HP VISA functions.
Block Transfers using This program performs a block transfer of 2,000 readings using the
HP E1563A digitizer and its VXIplug&play driver.
HP VXIplug&play Drivers
// 1563VPNP.CPP - This program transfers a block of 2,000 readings from the
// HP E1563 digitizer to the computer using the VXIplug&play driver’s
// hpe1563_fetchAll_Q function. 2,000 readings is the maximum number of
// readings that can be transferred using the function.
#include "hpe1563.h"// include the driver header file
#include <stdio.h>
#include <stdlib.h>
#include <windows.h>
// project files: 1563vpnp.cpp, hpe1563.lib
// Specify the addressing path.
#define E1563 "VXI0::64::INSTR"
// VXI addressing
// prototypes
void check(ViSession vi, ViStatus error);
void main(void)
{
ViSession vi;
ViStatus errStatus;
ViInt16 rdgs[2000];
ViInt16 *dataPtr;// pointer to cast readings to 16-bit integers
ViReal64 range;// range variable for reading conversions
int i;
long dataArrayLen=2000;// return 2,000 readings using
// hpe1563_fetchAll_Q
ViInt32 numRdgs;
ViChar err_message[256];
dataPtr = rdgs;// set pointer to rdgs array
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// open a VXIplug&play device session and reset the digitizer
errStatus = hpe1563_init(E1563,0,1,&vi);
if( VI_SUCCESS > errStatus)
{
hpe1563_error_message( vi, errStatus, err_message);
printf("Unable to open %s\n", E1563);
printf("hpe1563_init() returned error message %s\n", err_message);
return;
}
// enable digitizer error detection
hpe1563_errorQueryDetect(vi, 1);
// set a 5s timeout period to allow functions to complete
errStatus = hpe1563_timeOut(vi, 5000);
check(vi, errStatus);
// configure the digitizer to take 2,000 post-trigger readings
// not to exceed 4V on channel 1
errStatus=hpe1563_configure(vi, 1, 4.0, 2000,1);
check(vi, errStatus);
// set an immediate trigger
errStatus = hpe1563_trigEvent(vi, 1, hpe1563_TRIG_IMM, 0.0);
check(vi, errStatus);
// set the minimum sample period
errStatus = hpe1563_sampTim(vi, hpe1563_SAMP_TIM_MIN);
check(vi, errStatus);
// disable digitizer error detection
hpe1563_errorQueryDetect(vi, 0);
// initiate the digitizer
errStatus = hpe1563_initImm(vi);
// pause 3 ms (1.3e-6 * 2000) to allow readings to complete
Sleep (3);
// fetch readings from the digitizer’s A24 space
errStatus = hpe1563_fetchAll_Q(vi, dataArrayLen, (ViInt32 *)rdgs,
&numRdgs );
// confirm readings transferred are valid by printing first 5 readings
dataPtr = (ViInt16 *)rdgs;
// query digitizer reading range
errStatus = hpe1563_range_Q(vi, 1, &range);
printf("Reading samples are:\n\n");
for (i=0; i<10; i+=2)
{
printf("%lf\n\n",dataPtr[i]*range/32768);
}
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// reset digitizer following the transfer
errStatus = hpe1563_reset(vi);
// close the device session
hpe1563_close(vi);// HP VXIplug&play session
}
//***********************************************************************
// error checking routine
void check (ViSession vi, ViStatus errStatus)
{
ViInt32 inst_err;
ViChar err_message[256];
if(VI_SUCCESS > errStatus)
{
if(hpe1563_INSTR_ERROR_DETECTED == errStatus)
{
/* query instrument error */
hpe1563_dcl(vi);/* send a device clear */
hpe1563_error_query(vi, &inst_err, err_message);
/* display the error */
printf("Instrument Error : %ld, %s\n", inst_err, err_message);
}
else
{
/* get driver error message */
hpe1563_error_message(vi, errStatus, err_message);
/* display the error */
printf("HP E1563 Driver Error : %ld, %s\n", errStatus, err_message);
}
hpe1563_reset(vi);/* reset the digitizer */
hpe1563_close(vi);/* close the digitizer handle */
exit(1);
}
return;
}
Comments
1. The maximum block transfer size allowed by the HP E1563A
hpe1563_fetchAll_Q function is 2,000 bytes.
2. This manual is included on the HP I_O Libraries CD. By viewing the
manual from the CD, you can cut and paste this program into your
development environment.
3. The section “Using HP E8491A Shared Memory” contains an example of
block data transfers using HP SICL.
VXI Programming Using the IEEE 1394 Serial Bus
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Block Transfers using This program performs a block transfer of 60,000 readings using the
HP E1563A digitizer and the HP VISA function viMoveIn32.
HP VISA
// 1563visa.CPP - This program configures the HP E1563A digitizer using its
// VXIplug&play driver and then transfers a block of 60,000 readings from
// the digitizer’s FIFO memory to the computer using the VISA viMoveIn32
// function.
#include "hpe1563.h"// include the driver header file
#include "visa.h"
#include <stdio.h>
#include <stdlib.h>
#include <windows.h>
// project files: 1563visa.cpp, hpe1563.lib, VISA.lib
// specify the addressing path
#define E1563 "VXI0::64::INSTR"
// VXI addressing
// prototypes
void check(ViSession vi, ViStatus error);
void err_handler(ViSession vi, ViStatus err);
void main(void)
{
ViSession vi;
ViStatus errStatus, err;
ViInt32 rdgs[60000];
ViReal64 range;// range variable for reading conversions
ViInt16 *dataPtr;// pointer to cast readings to 16-bit integers
int i;
ViChar err_message[256];
// open a VXIplug&play device session and reset the digitizer
errStatus = hpe1563_init(E1563,0,1,&vi);
if( VI_SUCCESS > errStatus)
{
hpe1563_error_message( vi, errStatus, err_message);
printf("Unable to open %s\n", E1563);
printf("hpe1563_init() returned error message %s\n", err_message);
return;
}
// enable digitizer error detection
hpe1563_errorQueryDetect(vi, 1);
// set a 5s timeout period to allow functions to complete
errStatus = hpe1563_timeOut(vi, 5000);
check(vi, errStatus);
// configure the digitizer to take 60,000 post-trigger readings
// not to exceed 4V on channel 1
errStatus=hpe1563_configure(vi, 1, 4.0, 60000, 1);
check(vi, errStatus);
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// set an immediate trigger
errStatus = hpe1563_trigEvent(vi, 1, hpe1563_TRIG_IMM, 0.0);
check(vi, errStatus);
// set the minimum sample period
errStatus = hpe1563_sampTim(vi, hpe1563_SAMP_TIM_MIN);
check(vi, errStatus);
// disable digitizer error detection
hpe1563_errorQueryDetect(vi, 0);
// initiate the digitizer
errStatus = hpe1563_initImm(vi);
// pause 78 ms (1.3e-6 * 60000) to allow readings to complete
Sleep (78);
// transfer the (60,000) readings from the digitizer using the VISA
// function viMoveIn32 - use the same session name (vi) opened for
// VXIplug&play
err = viMoveIn32(vi, VI_A16_SPACE, 0x08, 60000, (ViPUInt32)rdgs);
if(err < VI_SUCCESS) err_handler(vi, err);
// confirm readings transferred are valid
dataPtr = (ViInt16 *)rdgs;
// query digitizer reading range
errStatus = hpe1563_range_Q(vi, 1, &range);
printf("Reading samples are:\n\n");
for (i=0; i<10; i+=2)
{
printf("%lf\n\n",dataPtr[i]*range/32768);
}
// reset digitizer following the transfer
errStatus = hpe1563_reset(vi);
// close the device session
hpe1563_close(vi);// HP VXIplug&play session
}
//************************************************************
// error checking routine
void check (ViSession vi, ViStatus errStatus)
{
ViInt32 inst_err;
ViChar err_message[256];
if(VI_SUCCESS > errStatus)
{
if(hpe1563_INSTR_ERROR_DETECTED == errStatus)
{
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/* query instrument error */
hpe1563_dcl(vi);/* send a device clear */
hpe1563_error_query(vi, &inst_err, err_message);
/* display the error */
printf("Instrument Error : %ld, %s\n", inst_err, err_message);
}
else
{
/* get driver error message */
hpe1563_error_message(vi, errStatus, err_message);
/* display the error */
printf("HP E1563 Driver Error : %ld, %s\n", errStatus, err_message);
}
hpe1563_reset(vi);/* reset the digitizer */
hpe1563_close(vi);/* close the digitizer handle */
exit(1);
}
return;
}
//************************************************************************
// Error handling function
void err_handler (ViSession vi, ViStatus err)
{
char buf[1024]={0};
viStatusDesc(vi,err,buf);
printf("ERROR = %s\n", buf);
return;
}
Comments
1. A single instrument session opened with the hpe1563_init function can be
used by both HP VXIplug&play driver function calls and by HP VISA
function (i.e viMoveIn32) calls.
2. This manual is included on the HP I_O Libraries CD. By viewing the
manual from the CD, you can cut and paste this program into your
development environment.
3. The section “Using HP E8491A Shared Memory” contains an example of
block data transfers using HP SICL.
42 VXI Programming Using the IEEE 1394 Serial Bus
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HP E8491A The HP E8491A is capable of asserting, receiving, and routing trigger
signals along the VXI (mainframe) backplane trigger lines. In addition to the
VXI backplane’s eight TTL level trigger lines and two ECL level trigger
Triggering
lines, the E8491A can receive and assert triggers on the faceplate ‘Trig In’
and ‘Trig Out’ connectors.
Table 3-1 summarizes the triggering parameters and capabilities of the
HP E8491A.
Table 3-1. HP E8491A Triggering Parameters.
Trigger Lines
Trigger Levels
Trigger Routing
TTLTRG7 - TTLTRG0
(VXI backplane)
Trigger levels or pulses can be
output on any number of
TTLTRG trigger lines.
One TTLTRG trigger line can be
routed to one ECLTRG trigger line.
ECLTRG1 - ECLTRG0 Trigger levels or pulses can be
One ECLTRG trigger line can be
routed to one TTLTRG trigger line.
(VXI backplane)
output on any number of
ECLTRG trigger lines.
Trig In Port*
Input trigger levels are TTL, ECL, Input triggers can be routed to any
(HP E8491A faceplate) CMOS, or programmable up to
+30V. Default assumes TTL low
true signal.
number of TTLTRG trigger lines and
to any number of ECLTRG trigger
lines.
Trig Out Port*
Output trigger level is +5V (low
One TTLTRG or ECLTRG trigger line
can be routed to the Trig Out port
(HP E8491A faceplate) true - default) and can be pulled
to +30V.
* The E8491A Trig In and Trig Out ports are configured using the HP I_O Libraries ‘I_O Config’
utility.
Using Triggers The triggering functionality of the HP E8491A is accessed through the
following HP VISA and SICL functions:
Asserting Triggers - HP VISA
viSetAttribute
VI_ATTR_TRIG_ID
VI_TRIG_TTL0 to VI_TRIG_TTL7
VI_TRIG_ECL0 to VI_TRIG_ECL1
viAssertTrigger
VI_TRIG_PROT_DEFAULT
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Asserting Triggers - HP SICL
ivxitrigoff
ivxitrigon
ixtrig
I_TRIG_ALL
I_TRIG_TTL0 to I_TRIG_TTL7
I_TRIG_ECL0 to I_TRIG_ECL1
I_TRIG_EXT0 (specifies faceplate ‘Trig Out’ port)
Routing Triggers- HP SICL
ivxigettrigroute
1
ivxitrigroute
I_TRIG_ALL
I_TRIG_TTL0 to I_TRIG_TTL7
I_TRIG_ECL0 to I_TRIG_ECL1
I_TRIG_EXT0 (specifies faceplate ‘Trig Out’ and ‘Trig In’ ports)
Configuring the E8491A Configuration of the E8491A external ‘Trig In’ and ‘Trig Out’ ports is done
through the HP I_O Libraries’ ‘I_O Config’ utility. This portion of the utility
is shown in the following figure.
Trig In and Trig Out Ports
Figure 3-1. Configuring the HP E8491A External Trigger Ports.
When ‘External Trig In’ is selected, the faceplate ‘Trig In’ port is configured
for the trigger level and state (normally high or normally low) selected.
When ‘External Trig Out’ is selected, the faceplate ‘Trig Out’ port is
configured for the state (normally high or normally low) selected.
1. Trigger routing is only available using the HP SICL ivxitrigroute function.
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Note The ‘I_O Config’ help file associated with the HP E8491A interface
contains additional information on configuring the faceplate trigger ports.
Triggering Example The following program demonstrates how an external trigger received on the
faceplate ‘Trig In’ port is routed to TTL trigger lines on the VXI backplane.
// TRIGSICL.CPP - This program demonstrates how trigger signals are
// generated and routed using the HP E8491A. The program uses SICL functions
// to generate and route a trigger signal from the face plate ‘Trig Out’
// port to VXI backplane trigger line TTLTRG4. The signal triggers the
// E1412 multimeter which then takes a burst of 10 readings.
#include "sicl.h"
#include <stdio.h>
#include <stdlib.h>
// project files: trigsicl.cpp, sicl32.lib
void main(void)
{
INST e8491;// E8491 SICL handle
INST e1412;// E1412 SICL handle
short i;
double dcv_rdgs[10];
// install SICL error handler
ionerror(I_ERROR_EXIT);
// open a (SICL) interface session to the E8491A
// open a (SICL) device session to the E1412
e8491 = iopen("vxi");
e1412 = iopen("vxi,24");
// set up trigger routing; rout a trigger from the faceplate 'Trig In'
// port to VXI backplane TTL trigger line 4
ivxitrigroute(e8491, I_TRIG_EXT0, I_TRIG_TTL4);
// E1412 Multimeter configuration
// set a 50s timeout period for external trigger to occur
itimeout(e1412, 50000);
// configure the multimeter for DCV measurements
iprintf(e1412, "CONF:VOLT:DC 8.0\n");
// set the fastest aperture time
iprintf(e1412, "VOLT:DC:APER MIN\n");
// turn off the autozero function
iprintf(e1412, "ZERO:AUTO OFF\n");
VXI Programming Using the IEEE 1394 Serial Bus
45
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// set the trigger source
iprintf(e1412, "TRIG:SOUR TTLT4\n");//trigger line 4
// set the sample count
iprintf(e1412, "SAMP:COUN 10\n");// 10 readings
// initiate the multimeter
iprintf(e1412, "INIT\n");
printf("Press ’Enter’ to trigger the voltmeter\n");
getchar ();
// output a trigger pulse on the E8491A ’Trig Out’ connector, the
// trigger is then input to the ’Trig In’ connector via a jumper wire
// and routed to TTL trigger line 4 which triggers the multimeter
ixtrig(e8491, I_TRIG_EXT0);
// fetch the readings once the trigger is received
ipromptf(e1412, "FETC?\n", "%,10lf", dcv_rdgs);
// display the readings
for (i=0; i<10; i++)
{
printf("%lf\n", dcv_rdgs[i]);
}
// close the device sessions
iclose(e8491);// close SICL interface session
iclose(e1412);// close SICL device session
}
Comments
1. For demonstation purposes, the trigger signal output from the ‘Trig Out’
port (ixtrig function) is routed to the ‘Trig In’ port using a jumper wire. The
signal is then routed to TTLTRG4 (ivxitrigroute function).
2. The external trigger routed to TTLTRG4 can also be routed to any or all
of the VXI backplane trigger lines.
3. When using the faceplate ‘Trig In’ and ‘Trig Out’ ports, notice that both
ports are specified using I_TRIG_EXT0.
In the program, ivxitrigroute(e8491s, I_TRIG_EXT0,
I_TRIG_TTL4)routes the trigger received on the faceplate ‘Trig In’ port
to backplane TTL trigger line 4. ixtrig(e8491s, I_TRIG_EXT0)
outputs a trigger pulse on the ‘Trig Out’ port which is connected by a
jumper wire to the ‘Trig In’ port.
4. This manual is included on the HP I_O Libraries CD. By viewing the
manual from the CD, you can cut and paste this program into your
development environment.
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Trigger Pull Up Trigger signals output from the E8491A ‘Trig Out’ port can be “pulled up”
to +30V as shown in Figure 3-2.
+V = pull up voltage (+30V max)
Output trigger state LH = normally low, high true
Output trigger state HL = normally high, low true (default)
Figure 3-2. Using a Pull Up on the HP E8491A ‘Trig Out’ Port.
Using HP E8491A The E8491A has 128 kBytes of shared (VME) memory. This memory is in
the E8491A’s A24 address space and is available to those VXI instruments
capable of mapping and accessing A24 memory. Shared memory is often
Shared Memory
used as a temporary storage space for data transfers between the PC and VXI
instruments.
HP instruments with the ability to store and receive data from shared
memory generally implement the SCPI (Standard Commands for
Programmable Instruments) MEMory:VME subsystem shown below:
MEMory:VME:SIZE
MEMory:VME:ADDRess
MEMory:VME:STATe
Corresponding HP VXIplug&play functions are:
hpexxxx_memVmeAddr
hpexxxx_memVmeSize
hpexxxx_memVmeStat
where xxxx is the instrument model number.
Locating E8491A Shared In order to use the E8491A shared memory, you must first locate the starting
address of the memory as mapped by the resource manager (see “Running
the Resource Manager” in Chapter 2). The address varies from system to
system depending on the number of devices that use A24 memory. The
address can be determined programatically using HP VISA or SICL, or by
viewing the resource manager output. Each method is described in the
following sections.
Memory
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Locating Shared Memory Using HP VISA
For HP VISA programs, the E8491A shared memory starting address is
obtained using the function:
viGetAttribute
and the VXI interface attribute:
VI_ATTR_MEM_BASE
The HP VISA version of the example “Storing Readings in Shared
Memory” demonstrates the use of this function and attribute.
Locating Shared Memory Using SICL
For SICL programs, the E8491A shared memory starting address is found
using the function:
ivxirminfo
This function fills the structure struct vxiinfo. The item within the structure
containing the starting address is memstart. The SICL version of the
example program showing the use of shared memory demonstrates the use
of this function and structure.
Locating Shared Memory by Viewing the Resource Manager
Output
The third method of determining the E8491A’s shared memory starting
address is to view the resource manager output. “Viewing the Resource
Manager Output” in Chapter 2 describes how this is done using the ‘I_O
Config’ utility. Figure 3-3 shows the section of the output that indicates A24
address mapping.
Another way to view the output is using the SICL ivxisc utility contained in
the <drive:>\siclnt\bin or sicl95\bin directory. This utility is an executable
that is used with the SICL logical unit number (see “Editing the HP E8491A
Configuration” in Chapter 2) to return the configuration output of the
resource manager. Again, Figure 3-3 shows a partial listing of the output.
Note Refer to Appendix B for additional information on using ivxisc and for an
example of the complete configuration output.
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starting address of E8491A shared
memory (hexadecimal)
Figure 3-3. Partial Listing of Resource Manager Output Showing Shared Memory Mapping.
Example Programs The following examples show an application using the E8491A’s shared
memory. In the program, 8,000 readings are taken with the HP E1410
multimeter. Because the E1410 has only enough memory to store 4,096
readings internally, all 8,000 readings are stored in shared memory and then
transferred to the PC. Given the shared memory size of 128 kBytes and the
E1410 storage format of eight bytes/reading, up to 16,000 readings can be
stored.
Figure 3-4 illustrates the reading transfers performed with the following
programs.
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Readings are taken and transferred from the
instrument to E8491A shared memory over
the VXI backplane.
DUT
Readings are transferred in blocks
from shared memory to the PC
over the IEEE 1394 serial bus.
Figure 3-4. Storing Readings in Shared Memory.
Storing Readings in This example uses the HP E1410 VXIplug&play driver to configure the
multimeter, take the readings, and store them in E8491A shared memory.
HP VISA functions are used to transfer the readings from shared memory to
the PC.
Shared Memory -
HP VISA Example
// SHAR_VISA.CPP - This program demonstrates how to access the
// HP E8491A’s shared memory. The program stores readings taken
// by the HP E1410 multimeter in HP E8491A shared memory, and then
// transfers those readings from shared memory to the computer.
#include "hpe1410.h"// include the driver header file
#include "visa.h"
#include <stdio.h>
#include <stdlib.h>
#include <windows.h>
// project files: SHAR_VISA.cpp, hpe1410.lib, VISA32.lib
// specify the addressing path to the multimeter
#define E1410 "VXI0::24::INSTR"
#define E8491 "VXI0::0::INSTR"
// E1410 path
// E8491 path
// check for instrument errors
#define INSTR_ERROR 0xBFFC0D07
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// set up byte swap function for readings transferred from
// E8491A shared memory to the PC
#define SWAP_FLOAT64(rdgs)
{ unsigned char src[8];
\
\
\
*((double *)src) = *((double *)rdgs);
((unsigned char *) (rdgs))[0] = ((unsigned char*) (src))[7]; \
((unsigned char *) (rdgs))[1] = ((unsigned char*) (src))[6]; \
((unsigned char *) (rdgs))[2] = ((unsigned char*) (src))[5]; \
((unsigned char *) (rdgs))[3] = ((unsigned char*) (src))[4]; \
((unsigned char *) (rdgs))[4] = ((unsigned char*) (src))[3]; \
((unsigned char *) (rdgs))[5] = ((unsigned char*) (src))[2]; \
((unsigned char *) (rdgs))[6] = ((unsigned char*) (src))[1]; \
((unsigned char *) (rdgs))[7] = ((unsigned char*) (src))[0]; \
}
// prototypes
void check(ViSession vi, ViStatus error);
void err_handler(ViSession vi, ViStatus err);
void main(void)
{
ViSession vi, defaultRM, fw;
ViStatus errStatus, err;
unsigned long start_addr;// starting address of shared memory
ViReal64 rdgs[8000];// array for readings from shared memory
int i;
ViChar err_message[256];
// open a VXIplug&play device session and reset the multimeter
errStatus = hpe1410_init(E1410,0,1,&vi);
if( VI_SUCCESS > errStatus)
{
hpe1410_error_message( vi, errStatus, err_message);
printf("Unable to open %s\n", E1410);
printf("hpe1410_init() returned error message %s\n", err_message);
return;
}
// open a VISA session to the E8491A
viOpenDefaultRM(&defaultRM);
viOpen(defaultRM,E8491, VI_NULL, VI_NULL, &fw);
// get E8491A shared memory base address
viGetAttribute(fw, VI_ATTR_MEM_BASE, &start_addr);
// enable multimeter error detection
hpe1410_errorQueryDetect(vi, 1);
// set a 5s timeout period to allow functions to complete
errStatus = hpe1410_timeOut(vi, 5000);
check(vi, errStatus);
// configure the multimeter for DCV measurements
errStatus = hpe1410_confVoltDc(vi);
check(vi, errStatus);
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// turn off autorange, set a 30V DCV range
errStatus = hpe1410_voltDcRang(vi, 0, 30);
check(vi, errStatus);
// set a 10 us aperture time
errStatus = hpe1410_voltDcAper(vi, 10.0e-6);
check(vi, errStatus);
// set 8000 readings
errStatus = hpe1410_sampCoun(vi, 8000);
check(vi, errStatus);
// store the readings in HP E8491A shared memory
// specify the E8491A shared memory base address
errStatus = hpe1410_memVmeAddr(vi, start_addr);
check(vi, errStatus);
// specify the amount of memory required
// (8000 readings * 8 bytes/reading)
errStatus = hpe1410_memVmeSize(vi, 64000);
check(vi, errStatus);
// enable the readings to be stored
errStatus = hpe1410_memVmeStat(vi, 1);
// disable multimeter error detection
hpe1410_errorQueryDetect(vi, 0);
// initiate the multimeter to take the readings
errStatus = hpe1410_initImm(vi);
// pause 30s to allow readings to complete
Sleep (30000);
// transfer the 8,000 readings (64,000 bytes) from the multimeter using
// the VISA function viMoveIn8
err = viMoveIn8(fw, VI_A24_SPACE, 0, 64000, (ViPUInt8)rdgs);
if(err < VI_SUCCESS) err_handler(fw, err);
// swap the bytes once they are transferred from shared memory
for (i=0;i<7999;i++)
{
SWAP_FLOAT64(&rdgs[i]);
}
// print some readings to verify the transfer was successful
for (i=0; i<10; i++)
{
printf("%lf\n", rdgs[i]);
}
// close the device sessions
hpe1410_close(vi); // close E1410 session
viClose(fw);
// close E8491 session
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}
//**********************************************************
// error checking routine
void check (ViSession vi, ViStatus errStatus)
{
ViInt32 inst_err;
ViChar err_message[256];
if(VI_SUCCESS > errStatus)
{
if(INSTR_ERROR == errStatus)
{
// query instrument error
hpe1410_dcl(vi);// send a device clear
hpe1410_error_query(vi, &inst_err, err_message);
// display the error
printf("Instrument Error : %ld, %s\n", inst_err, err_message);
}
else
{
// get driver error message
hpe1410_error_message(vi, errStatus, err_message);
// display the error
printf("HP E1410 Driver Error : %ld, %s\n", errStatus, err_message);
}
hpe1410_reset(vi);// reset the multimeter
hpe1410_close(vi);// close the multimeter handle
exit(1);
}
return;
}
//**************************************************************
// Error handling function
void err_handler (ViSession vi, ViStatus err)
{
char buf[1024]={0};
viStatusDesc(vi,err,buf);
printf("ERROR = %s\n", buf);
return;
}
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Comments
1. Because of the E1410 multimeter data storage format (eight bytes /
reading), the readings are transferred from shared memory to the PC in
bytes. Therefore, it is necessary to swap each byte in order to re-construct
the reading. Depending on the storage formats of your particular
instruments, swapping may not be necessary.
2. This manual is included on the HP I_O Libraries CD. By viewing the
manual from the CD, you can cut and paste this program into your
development environment.
Storing Readings in This example uses the HP E1410 VXIplug&play driver to configure the
multimeter, take the readings, and store them in E8491A shared memory.
SICL functions are used to transfer the readings from shared memory to the
PC.
Shared Memory - SICL
Example
// SHAR_SICL.CPP - This program demonstrates how to access the
// HP E8491A’s shared memory. The program stores readings taken by
// the HP E1410 multimeter in HP E8491A shared memory, and then
// transfers those readings from shared memory to the computer.
#include "sicl.h"
#include <stdio.h>
#include <stdlib.h>
#include <windows.h>
// project files: SHAR_SICL.cpp, SICL32.lib
// set up byte swap function for readings transferred from
// E8491A shared memory to the PC
#define SWAP_FLOAT64(rdgs) \
{ unsigned char src[8];
\
*((double *)src) = *((double *)rdgs);
\
((unsigned char *) (rdgs))[0] = ((unsigned char*) (src))[7]; \
((unsigned char *) (rdgs))[1] = ((unsigned char*) (src))[6]; \
((unsigned char *) (rdgs))[2] = ((unsigned char*) (src))[5]; \
((unsigned char *) (rdgs))[3] = ((unsigned char*) (src))[4]; \
((unsigned char *) (rdgs))[4] = ((unsigned char*) (src))[3]; \
((unsigned char *) (rdgs))[5] = ((unsigned char*) (src))[2]; \
((unsigned char *) (rdgs))[6] = ((unsigned char*) (src))[1]; \
((unsigned char *) (rdgs))[7] = ((unsigned char*) (src))[0]; \
}
void main(void)
{
INST e8491;
INST e1410;
struct vxiinfo info;
// handle for SICL session to E8491
// handle for SICL session to E1410
// structure for data returned by ivxirminfo
unsigned long start_addr; // starting address of shared memory
double rdgs[8000];
short i;
unsigned long map;
// array for readings from shared memory
// memory map space
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// install SICL error handler
ionerror(I_ERROR_EXIT);
// open a (SICL) interface session to the E8491A
// open a (SICL) device session to the E1410
e8491 = iopen("vxi");
e1410 = iopen("vxi,24");
// read the VXI resource manager information in order to determine
// the E8491A shared memory starting address
ivxirminfo(e8491, 0, &info);
start_addr = info.memstart;
// convert address from pages to an address
start_addr = (start_addr*256);
// map E8491A memory space for transfer of readings from
// E8491A shared memory to the computer
map = imapx(e8491, I_MAP_SHARED, 0, 1);
// set a 5s timeout period to allow functions to complete
itimeout(e8491, 5000);
itimeout(e1410, 5000);
// configure the multimeter for DCV measurements
iprintf(e1410, "CONF:VOLT:DC 30.0\n");
// set a 10 us aperture time
iprintf(e1410, "VOLT:APER 10.0e-6\n");
// set 8000 readings
iprintf(e1410, "SAMP:COUN 8000\n");
// store the readings in HP E8491A shared memory
// specify the E8491A shared memory base address
iprintf(e1410, "MEM:VME:ADDR %d\n", start_addr);
// specify the amount of memory required
// (8000 readings * 8 bytes/reading)
iprintf(e1410, "MEM:VME:SIZE 64000\n");
// enable the reading to be stored
iprintf(e1410, "MEM:VME:STAT 1\n");
// initiate the multimeter to take the readings
iprintf(e1410, "INIT\n");
// pause 30s to allow readings to complete and to transfer
// to shared memory
Sleep (30000);
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// transfer the (8000) readings from the multimeter using the SICL
// function iblockmovex - the parameters are id, source handle, source
// offset, source width, source increment, destination handle, destination
// offset, destination width, destination increment, count, and swap
iblockmovex(e8491, map, 0, 8, 1, 0, (unsigned long) rdgs, 8, 1, 64000, 0);
// swap the bytes once they are transferred from shared memory
for (i=0;i<7999;i++)
{
SWAP_FLOAT64(&rdgs[i]);
}
// print some readings to verify the transfer was successful
for (i=0; i<10; i++)
{
printf("%lf\n", rdgs[i]);
}
// unmap memory
iunmapx(e8491, map, I_MAP_SHARED, 0, 1);
// close the device sessions
iclose(e8491);// close SICL interface session
iclose(e1410);// close SICL device session
}
Comments
1. Because of the E1410 multimeter data storage format (eight bytes /
reading), the readings are transferred from shared memory to the PC in
bytes. Therefore, it is necessary to swap each byte in order to re-construct
the reading. Depending on the storage formats of your particular
instruments, swapping may not be necessary.
2. This manual is included on the HP I_O Libraries CD. By viewing the
manual from the CD, you can cut and paste this program into your
development environment.
56 VXI Programming Using the IEEE 1394 Serial Bus
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Chapter 4
IEEE 1394 Fundamentals and
Interface Overview
Using this Chapter
This chapter contains reference information on the IEEE 1394 Serial Bus,
the data transfer protocol, and on the related hardware. The contents of the
chapter include:
®
IEEE 1394 Topology Optimizing the IEEE 1394 bus must include an understanding of the
topology and terms associated with its use. Figure 4-1 shows a VXI system
consisting of a PC and three VXI mainframes - interconnected with the IEEE
and Terminology
1394 bus.
PC w/ IEEE 1394-to-PCI
host adapter
VXI mainframe 1
VXI mainframe 3
hop
root
node
parent
child
branch
node
leaf
node
hop
hop
VXI mainframe 2
child
HP E8491A IEEE 1394
to VXI interconnect
leaf
node
Figure 4-1. IEEE 1394 Topology and Terms.
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The terms shown in Figure 4-1 are defined in the following table.
Table 4-1. Definition of Terms.
Host Adapter Links the computer’s PCI bus to the IEEE 1394 interface. To use a
host adapter, computers must be PCI Rev. 2.0 compliant.
HP E8491A
1394-to-VXI
Interconnect
Links the IEEE 1394 interface to the VXI backplane. Provides the
backplane’s clock and trigger resources.
Root Node
Each device (HP E8491A) on the bus is a “node.” In VXI systems,
the PC is always the root node having cycle master and bus master
capabilities.
Branch Node A branch node has IEEE 1394 cables connected to two or more
ports. In Figure 1, VXI mainframe 1 is a branch node because of the
1394 cables connecting it to the PC (root node) and to VXI
mainframe 3 on its right.
Leaf Node
A leaf node has a single IEEE 1394 cable connected to it.VXI
mainframes 2 and 3 are leaf nodes.
Parent
A node (HP E8491A) is a parent if it is physically connected closer
to the root than an adjacent node. In Figure 1, VXI mainframe 1 is a
parent node because it is closer to the root than VXI mainframe 3.
Child
Hop
A node (HP E8491A) is a child if it is farther from the root than an
adjacent node. In Figure 1, VXI mainframe 3 is a child node
because it is farther from the root than VXI mainframe 1.
A node with a single IEEE 1394 cable connected to it (leaf node) is
always a child (VXI mainframe 2).
A hop is a IEEE 1394 cable link between nodes. There can be no
more than 16 hops between any two nodes. In the diagram above,
there is a maximum of three hops between nodes. The distance
between any two nodes cannot exceed 72m.
Features of the The following features of the IEEE 1394 bus apply to all bus applications
including VXI systems.
IEEE 1394 Bus
* Daisy-chain or branching configurations are allowed. There can be no
closed loops (i.e. more than one connection between any two devices).
* Up to 63 devices (including 16 HP E8491As) are allowed per bus segment.
One host adapter represents one bus segment.
* There is a maximum of 16 hops between any two devices. The bus cable
length cannot exceed 72 meters between any two devices.
* Live/hot connections. A VXI mainframe anywhere in the configuration
can be turned on/off without affecting the other mainframes. The IEEE 1394
bus automatically reconfigures itself any time a VXI mainframe (or other
device) is added or removed. It is best to do this however, if there are no
data transactions taking place elsewhere in the system.
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Optimizing the I/O performance is impacted slightly by the hardware configuration.The
VXI mainframe closest to the PC (root node) has the highest priority. For
example, if instruments in VXI mainframes 1 and 3 (Figure 4-1) contend for
the bus at the same time, the root node will grant mainframe 1 access to the
bus first. However, the bus’s fair arbitration protocol (covered in the next
section) ensures that each device has equal access to the bus and that devices
closer to the root are not continually granted the bus.
Configuration
IEEE 1394 Data transfer over the IEEE 1394 bus can be either asynchronous or
1
isochronous . Hewlett-Packard’s IEEE 1394 based VXI systems use
Data Transfer
asynchronous data transfers and a “fair arbitration” protocol to ensure each
VXI mainframe has equal access to the bus. Figure 4-2 illustrates the
concepts of asynchronous data transfers and fair arbitration.
Protocol
VXI mainframe 1
VXI mainframe 3
block transfer
block transfer
VXI mainframe 2
data packet
data packet
data packet
data packet
data packet
data packet
F I
Fairness Interval
F I
n-1
n
n+1
mainframe 1 or 2
mainframe 1 or 2
mainframe 3
arb
seq
data
packet
arb
seq
data
packet
arb
seq
data
packet
ack
ack
ack
subaction 1
subaction 2
subaction 3
subaction gaps
arbitration rest gap
arbitration gap
Figure 4-2. IEEE 1394 Data Transfer Protocol.
1. Isochronous data transfers broadcast variable amounts of data at regular intervals with no acknowledgement.
Isochronous and Asynchronous data transfers can occur on the same bus.
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Asynchronous Data During an asynchronous data transfer, a variable amount of data is
transferred to an explicit address in real time, and an acknowledgement is
returned. Data is transferred across the IEEE 1394 bus in packets called
“subactions.” An asynchronous subaction is made up of three parts:
Transfers
* arbitration sequence - the period when a device requests control of the bus
in order to transmit a data packet.
* data packet - the data packet consists of a data prefix that contains
information about the transaction, the data itself (e.g. VXI instrument
commands), and a data end signal. The maximum packet size is 1 kByte for
200 Mbit host adapters and 2 kBytes for 400 Mbit adapters.
* acknowledgement - a code returned by the (addressed) data destination
indicating the action taken by the receiver.
The periods between subactions are called subaction gaps. The subaction
gap allows devices that have not had control of the bus during the current
“fairness interval” to arbitrate for control.
Fair Arbitration Protocol The fair arbitration protocol is based on the fairness interval shown in Figure
2. A fairness interval consists of one or more subactions in which data
packets are transferred over the bus. A fairness interval is as follows:
1. The interval begins when devices (HP E8491A’s) arbitrate for control of
the bus.
2. When a device is granted control, it transfers its data packet and is then
disabled from arbitrating until the next fairness interval.
3. A subaction gap occurs after the previous data packet is transferred.
During this period, remaining devices arbitrate for the bus. The next device
granted the bus transfers its data packet and is then disabled from arbitrating
until the next fairness interval.
4. The fairness interval ends after each device has had an opportunity to
access to the bus and the arbitration reset gap, which is longer than the
subaction gap, occurs. The arbitration reset gap re-enables each device for
arbitration during the next fairness interval.
VXI Data Transfers To take advantage of the IEEE 1394 data transfer protocol, large amounts of
data should be transferred between VXI instruments and the PC using block
transfers. During a block transfer, data is divided into the packets described
previously; the number of packets depends on the amount of data and
whether a 200 Mbit or 400 Mbit host adapter is used. Compared to protocols
that transfer data one byte or one word at a time, transfer speed between the
instrument and the PC is increased because the IEEE 1394 protocol
overhead is associated with the fairness interval and with each packet, rather
than with each byte or word transferred. Thus, transfer speeds (bits/second)
over the IEEE 1394 bus increase as the amount of data transferred (block
size) increases.
60 IEEE 1394 Fundamentals and Interface Overview
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1
®
The Adaptec
AHA-8940 Host
The Adaptec® AHA-8940 1394-to-PCI host adapter is a PC plug-in card
capable of transferring data at up to 400 MBits/second. The adapter has one
internal and two external 1394 ports. Each AHA-8940 represents one bus
Adapter and segment capable of supporting up to 63 nodes. If required, the AHA-8940
can supply 12V at up to 1.5A for IEEE 1394 devices that require power.The
Interface Cable
layout of the adapter is shown below.
12 VDC power connector
Internal IEEE 1394 connector
External
IEEE 1394
connectors
Figure 4-3. Layout of the Adaptec® AHA-8940 1394-to-PCI Host Adapter.
The interface cable supplied with the host adapter has two power wires and
two signal twisted-pairs. A cross-section of the cable and the cable
connector are shown in Figure 4-4.
1. In the future, IEEE 1394 will be a standard port on selected PCs.
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shields
signal pair wires
connector
1
2
3
4
5
6
PIN #
COMMENT
cable power
cable ground
6.1 mm
1
2
strobe on receive,
data on transmit
3/4
5/6
data on receive,
strobe on transmit
power wires
Figure 4-4. Cross-section of the IEEE 1394 Cable.
The power wires route power from the host adapter to devices (nodes) on the
bus, whether the devices are turned on or off. Since each device in the
system acts as a repeater, the power supplied to a device that is turned off
enables signals to be transferred across that device. This maintains signal
continuity throughout the system.
The HP E8491A PC The E8491A is a VXI C-size device (Figure 4-5) normally installed in
mainframe slot 0. With a logical address of 0, the E8491A functions as the
mainframe’s resource manager via software included with the I_O libraries.
to VXI Interconnect
The E8491A has 128 kBytes of shared RAM and contains many of the clock
and triggering features found on the HP E1406A Command Module - a VXI
resource manager/slot 0 device common in many GPIB-based systems. A
VXI mainframe with the HP E8491A in slot 0 can also be powered on/off at
any time without affecting other mainframes in the system.
The HP E8491A IEEE 1394 interconnect links the VXI backplane to the
IEEE 1394 bus. However, the E8491A and the IEEE 1394 bus do not extend
the (VXI) backplane between frames in multi-frame VXI systems. This
means that the multimeter and multiplexers in a VXI scanning multimeter
for example, must be installed in the same mainframe. Devices sharing the
VXI Local bus must also be installed in the same mainframe.
62 IEEE 1394 Fundamentals and Interface Overview
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Annunciators
Failed - a hardware failure
was detected in the HP E8491A,
or the E8491A is performing a
self-test.
IEEE-1394- indicatesdata traffic
over the IEEE 1394 bus
SYSFAIL - asserted during a VXI
instrument self-test.
IEEE 1394 Ports
VXI - indicates data traffic across
the mainframe’s VXI backplane.
Three ports allow tree topologies
which minimize the number of hops.
Each port is identical and any port or
combination of ports can be used.
Trigger Ports
The E8491A is capable of sourcing
TTL level triggers and receiving
TTL, CMOS, ECL, or user
specified levels up to +30V.
Trigger signals can be generated
internally and distributed over the
VXI backplane and to external de-
vices, or the triggers can be distrib-
uted from an external source.
System Clock Ports
The E8491A is capable of sourcing and
receiving the VXI system’s 10 MHz clock.
The system clock (CLK10) is one of the
VXI resources provided by the
mainframe’s slot 0 device. This TTL level
clock is internally generated or can be
received from an external source. The
signal is distributed to every slot in the
mainfame and can also be routed to
external devices.
Configuration Label
Used to identify the interconnect
address in multi-frame VXI
systems.
Reset Button
Resets the E8491A and all
instruments in the mainframe.
Re-runs the resource manager.
Figure 4-5. The HP E8491A IEEE 1394 to VXI Interconnect.
IEEE 1394 Fundamentals and Interface Overview
63
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Using the HP E8491A Though not a common configuration, the HP E1406 command module can
be used in the same mainframe as the HP E8491 to provide HP-IB access to
instruments. In this configuration, however, the E8491A must be the
mainframe’s resource manager.
with the HP E1406
Command Module
The HP I_O The software required to use the IEEE 1394 interface in a VXI system is
contained in the HP I_O Libraries and HP VXIplug&play Drivers. The
Libraries
software supports the Windows 95 and Windows NT platforms.
The software “stack” shown below shows the relationship of the
VXIplug&play drivers to HP VISA/ SICL, to the host adapter drivers, and
to the VXI instruments. Notice that Hewlett-Packard’s implementation of
the IEEE 1394 interface requires HP VISA and will not work with the VISA
supplied by other vendors.
Development Environment
(C/C++, Visual BASIC, HP VEE)
HP Universal Instrument
Drivers
HP VXI plug&play Instrument
Drivers
HP VISA / HP SICL
Host Adapter Drivers
VXI Instruments
HP I_O Libraries
Figure 4-6. System Software and Drivers.
Most application programs are written using the instruments’
VXIplug&play drivers. The plug&play driver functions make subsequent
calls to the VISA functions and so on. Message-based instruments can be
programmed at the HP VISA / SICL level by embedding SCPI commands
in the HP VISA / SICL functions.
64 IEEE 1394 Fundamentals and Interface Overview
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Appendix A
Specifications
The following specifications define the operating and performance
characteristics of the HP E8491A.
Interface
Characteristics
Operating System
Windows 95
Windows NT
Controllers
I/O Library
PC based
SICL / VISA
Backplane
PCI
Interface
IEEE 1394
Maximum I/O Speed*
16-bit: 1.76 MBytes/s to PC
2.50 MBytes/s to HP E8491A
* 200 MHz Pentium PC
32 bit: 1.0 MByte/s to PC
1.0 MByte/s to HP E8491A
/
400 MHz Adaptec Host
Languages
C/C++, Visual Basic, HP VEE, LabView
VXI Characteristics
General
VXI Device Type
Data transfer bus
Slot 0 functionality
Message-based commander
n/a
Yes
Resource Manager Functionality
MXIbus Resource Manager
Size
Yes
Yes
C
Slots
1
Connectors
P1 / P2
Shared Memory
VXI busses
128 kBytes
TTL trigger bus, ECL trigger bus
n/a
C-size compatibility
Specifications
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CLK 10
Clk In
Input
TTL
Frequency Stability
Duty Cycle
100 ppm
50% ± 5%
Clk Out
Output
TTL
Frequency Stability
Duty Cycle
100 ppm
50% ± 5%
External Trigger Input
Connector
Levels
SMB (on faceplate)
TTL, CMOS, ECL, 0 to +33V
0 to +30V
Programmable Threshold
Range
Programmable Threshold
Accuracy
± 0.4V
Threshold Sensitivity
(hysteresis)
0.5 Vpp maximum
0.1 Vpp minimum
Input Load
Maximum Rate
50 pf, 55 kohms
2 MHz
Minimum Pulse Width
200 ns
External Trigger Output
Connector
Levels
SMB (on faceplate)
nominal pull up to + 5V
+ 30V
Maximum External Pull Up
Sink Current
10 mA @ Vol < 0.4V or
150 mA @ Vol < 1.0V
66 Specifications
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Trigger Delays
Maximum delay from TTLTRG to
ECLTRG
60 ns
60 ns
Maximum delay from ECLTRG to
TTLTRG
Maximum delay from Trig In port
to ECLTRG or TTLTRG
300ns
100 ns
Maximum delay from TTLTRG or
ECLTRG to Trig Out port
Cooling
Watts / slot
20W
0.10
P mm H 0
∆
2
Air flow liters / s
2.0
Power Supply Loading
IPM (amps)
IDM (amps)
+5V
+12V
-12V
+24V
-24V
-5.2V
-2V
2.5
0.35
0.015
0.0
0.001
0.050
0.001
0.0
0.0
0.0
0.180
0.360
0.001
0.001
Specifications
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Appendix B
Editing the HP E8491A Resource Manager
Configuration
Introduction
The resource manager functionality provided through the HP E8491A
configures your VXI system based on rules specified by the VXI standard.
The configuration can be viewed or modified through the configuration files
and utility functions outlined in this appendix.
Configuration File Configuration files (.cf extension) are placed in the <drive:>\siclnt\defaults
or \sicl95\defaults directory when the HP I_O Libraries are installed. Except
where noted, the following files can be edited from the HP I_O Libraries’
Overview
‘I_O Config’ utility (Figure B-1) as shown on the following pages. When
editing a file, note the following:
1. Add your entry(ies) below the commented (lines).
2. The first column must contain an entry. Any number of spaces can
separate remaining entries on the line.
Editing the HP E8491A Resource Manager Configuration
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1. From the I_O Libraries program
group, click I_O Config.
2. Select the configured
HP E8491A interface and then
click Edit. This brings up the
window (partial view) in Figure
B-2.
Figure B-1. Editing Configuration Files from the ‘I_O Config’ Utility.
70 Editing the HP E8491A Resource Manager Configuration
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3. Check Enable Advanced and then
click Resource Manager...
4. Select the portion of the configuration
to edit and then click Edit.
Figure B-2. Editing Configuration Files from the ‘I_O Config’ Utility (cont’d).
Editing the HP E8491A Resource Manager Configuration
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The names.cf The names.cf file is a database that contains a list of symbolic names to
assign VXI devices that have been configured. The ivxirm utility reads the
model id number from the VXI device and the ivxisc utility uses that
information and this file to print out the VXI device symbolic name. If you
add a new VXI device to your system that is not currently in the database,
you may want to add an entry to this file.
Configuration File
This file is edited by selecting “Add/delete symbolic names of VXI devices”
in the Resource Manager window (Figure B-2).
The oride.cf The oride.cf file contains values to be written to logical address space for
register-based instruments. This data is written to A16 address space after
Configuration File
the resource manager runs, but before the system’s resources are released.
This can be used for custom configuration of register-based instruments
every time the resource manager runs.
This file is edited by selecting “Add/delete values to be written to logical
address space” in the Resource Manager window (Figure B-2).
The vmedev.cf The vmedev.cf file contains a list of VME devices that use resources in the
VXI cardcage. Since the resource manager is unable to detect VME devices,
Configuration File
the resource manager uses this information to determine such things as the
slot number where the VME device is located, what type (A16, A24, or A32)
and how much memory it uses, and what interrupt lines it uses. Additionally,
the resource manager verifies that multiple resources aren’t allocated. This
file is also used by the ivxisc utility to print out information about the
devices.
This file is edited by selecting “Add/delete VME devices that use resources”
in the Resource Manager window (Figure B-2).
The cmdrsrvt.cf The cmdrsrvt.cf file contains a commander/servant hierarchy other than the
default for the VXI system. The resource manager will set up the
Configuration File
commander/servant hierarchy according to the commander’s logical
addresses and the servant area switch. However, you can use this file to
override the default based on the commander’s servant area. This file should
only contain changes from the default.
This file is edited by selecting “Edit commander/servant hierarchy” in the
Resource Manager window (Figure B-2).
The dynamic.cf The dynamic.cf file contains a list of VXI devices to be dynamically
configured. You only need to add entries to this file if you want to override
Configuration File
the default dynamic configuration assignment by the resource manager.
Normally, if you have a dynamically configurable device and the logical
address is set at 255, the resource manager will assign the first available
address. However, if a dynamically configurable device has an entry in this
file, the resource manager will assign the address listed in the file.
This file is edited by selecting “Edit list of dynamically configured devices”
in the Resource Manager window (Figure B-2).
72 Editing the HP E8491A Resource Manager Configuration
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The irq.cf Configuration The irq.cf file is a database that maps specific interrupt lines to VXI interrupt
handlers. If you have non-programmable interrupters and you want the
interrupters to be recognized by a VXI interrupt handler, you must make an
entry in this file. Additionally, if you have progammable interrupters and
you want them to be recognized by a device other than what’s assigned by
the resource manager (the commander of that device), you can make an
entry in this file to override the default. Keep in mind that not all VXI
devices need to use interrupt lines and not all interrupt lines need to be
assigned. Note that any interrupt lines assigned in this file cannot also be
assigned in the vmedev.cf configurtion file.
File
This file is edited by selecting “Edit mapping of VXI devices to interrupt
lines” in the Resource Manager window (Figure B-2).
The ttltrig.cf The ttltrig.cf file contains the mapping of VXI devices to TTL trigger lines
in extended VXI systems. If you have a MXI-extended
(multiple-mainframe) system and you are sending / receiving triggers
between mainframes, you must map the TTL trigger line to the logical
address of the device asserting the trigger. This file is only used for extended
VXI systems.
Configuration File
This file is edited by selecting “Edit mapping of VXI devices to ttl trigger
lines” in the Resource Manager window (Figure B-2).
The vximanuf.cf The vximanuf.cf file contains a database that cross references the VXI
manufacturer id numbers and the name of the manufacturer. The ivxirm
Configuration File
utility reads the manufacturer id number from the VXI device. The ivxisc
utility then uses that number and this file to print out the name of the
manufacturer. If you add a new VXI device from a vendor that is not
currently in the file, you may want to add an entry to the file.
This file can not be edited using ‘I_O Config’.
The vximodel.cf The vximodel.cf file contains a database that lists a cross reference of
manufacturer id, model id, and VXI device names. The ivxirm utility reads
Configuration File
the model id number from the VXI device and the ivxisc utility uses that
information and this file to print out the VXI device model. If you add a new
VXI device to your system that is not currently in this database, you may
want to add an entry to this file.
This file can not be edited using ‘I_O Config’.
Utility Function Within the <drive:>\siclnt\bin or \sicl95\bin directory are utility functions
that view the resource manager output (ivxisc) and which clear the
HP E8491A interface (iclear) and run the resource manager (if the iproc
Overview
utility is running).
Using ivxisc The ivxisc function is used to view the resource manager output. ivxisc is
executed from the Windows command (DOS) prompt (..\siclnt\bin or
\sicl95\bin directory) as:
ivxisc vxi<logical unit>
Editing the HP E8491A Resource Manager Configuration
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where <logical unit>is the value from the ‘Logical Unit’ window in
the HP I_O Libraries ‘I_O Config’ utility. An example of the output
produced by ivxisc is shown in Figures B-3 and B-4.
Figure B-3. Output of ivxisc.
74 Editing the HP E8491A Resource Manager Configuration
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Figure B-4. Output of ivxisc (cont’d).
Using iclear The iclear function is used to clear the interface (HP E8491A) or individual
message-based instruments in the VXI mainframe. iclear is executed from
the DOS command prompt (..\siclnt\bin or \sicl95\bin directory) as:
iclear <SICL interface name, [logical address]>
SICL interface nameis the name (vxi) and number listed in the ‘I_O
Config’ SICL Interface Name window. logical addressis the
address of the message-based VXI instrument to be cleared.
If a logical address is not specified, the (E8491A) interface is cleared and the
resource manager is started.
Editing the HP E8491A Resource Manager Configuration
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76 Editing the HP E8491A Resource Manager Configuration
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Index
HP E8491A IEEE 1394 PC Link to VXI
Configuration and User’s Guide
A
E
E1406
E8491A
examples
B
C
CLK 10
configuration files
external trigger input
external trigger output
F
H
host adapter and interface cable
HP E1406
using the command module with the HP
HP E8491A
HP I/O Libraries
HP VXIplug&play drivers
D
data transfers
Index
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I
O
I/O Libraries
IEEE 1394
IEEE 1394 host adapter
P
plug&play drivers
installation
programming register-based and message-based VXI
pull up
instrument sessions
interface cable and host adapter
interface characteristics
R
register-based instruments
resource manager configuration
S
SICL programs
soft front panels
L
loading
locating shared memory
specifications
M
message-based instruments
MXI
N
storing readings in shared memory
78 Index
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T
Trig In
Trig In port
Trig Out port
trigger delay
U
using the HP E8491A with the HP E1406 Command
V
VXI characteristics
VXI instruments
VXI-MXI systems
VXIplug&play drivers
Index
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