National Instruments VXI-AT2000 User manual

© Copyright 1989, 1994 National Instruments Corporation.
All Rights Reserved.
Getting Started with Your
VXI-AT2000 and the
NI-VXI™Software for MS-DOS
bus
October 1993 Edition
Part Number 320219-01

National Instruments Corporate Headquarters
6504 Bridge Point Parkway
Austin, TX 78730-5039
[phone]
Technical support fax: [phone]
[phone]
Branch Offices:
Australia [phone], Austria [phone], Belgium 02/757.00.20, Canada (Ontario) [phone],
Canada (Québec) [phone], Denmark 45 76 26 00, Finland (90) 527 2321, France (1) 48 14 24 24,
Germany 089/741 31 30, Italy 02/48301892, Japan [phone], Netherlands 03480-33466, Norway 32-848400,
Spain (91) 640 0085, Sweden 08-730 49 70, Switzerland 056/20 51 51, U.K. 0635 523545

Limited Warranty
The National Instruments MXIbus boards and accessories are warranted against defects in materials and
workmanship for a period of one year from the date of shipment, as evidenced by receipts or other documentation.
National Instruments will, at its option, repair or replace equipment that proves to be defective during the warranty
period. This warranty includes parts and labor.
The media on which you receive National Instruments software are warranted not to fail to execute programming
instructions, due to defects in materials and workmanship, for a period of 90 days from date of shipment, as
evidenced by receipts or other documentation. National Instruments will, at its option, repair or replace software
media that do not execute programming instructions if National Instruments receives notice of such defects during
the warranty period. National Instruments does not warrant that the operation of the software shall be uninterrupted
or error free.
A Return Material Authorization (RMA) number must be obtained from the factory and clearly marked on the
outside of the package before any equipment will be accepted for warranty work. National Instruments will pay the
shipping costs of returning to the owner parts which are covered by warranty.
National Instruments believes that the information in this manual is accurate. The document has been carefully
reviewed for technical accuracy. In the event that technical or typographical errors exist, National Instruments
reserves the right to make changes to subsequent editions of this document without prior notice to holders of this
edition. The reader should consult National Instruments if errors are suspected. In no event shall National
Instruments be liable for any damages arising out of or related to this document or the information contained in it.
EXCEPT AS SPECIFIED HEREIN, NATIONAL INSTRUMENTS MAKES NO WARRANTIES, EXPRESS OR IMPLIED,
AND SPECIFICALLY DISCLAIMS ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR
PURPOSE. CUSTOMER'S RIGHT TO RECOVER DAMAGES CAUSED BY FAULT OR NEGLIGENCE ON THE PART
OF NATIONAL INSTRUMENTS SHALL BE LIMITED TO THE AMOUNT THERETOFORE PAID BY THE CUSTOMER.
NATIONAL INSTRUMENTS WILL NOT BE LIABLE FOR DAMAGES RESULTING FROM LOSS OF DATA, PROFITS,
USE OF PRODUCTS, OR INCIDENTAL OR CONSEQUENTIAL DAMAGES, EVEN IF ADVISED OF THE POSSIBILITY
THEREOF. This limitation of the liability of National Instruments will apply regardless of the form of action,
whether in contract or tort, including negligence. Any action against National Instruments must be brought within
one year after the cause of action accrues. National Instruments shall not be liable for any delay in performance due
to causes beyond its reasonable control. The warranty provided herein does not cover damages, defects,
malfunctions, or service failures caused by owner's failure to follow the National Instruments installation, operation,
or maintenance instructions; owner's modification of the product; owner's abuse, misuse, or negligent acts; and
power failure or surges, fire, flood, accident, actions of third parties, or other events outside reasonable control.
Copyright
Under the copyright laws, this publication may not be reproduced or transmitted in any form, electronic or
mechanical, including photocopying, recording, storing in an information retrieval system, or translating, in whole
or in part, without the prior written consent of National Instruments Corporation.
Trademarks
LabVIEW®and NI-VXI™are trademarks of National Instruments Corporation.
Product and company names listed are trademarks or trade names of their respective companies.

Warning Regarding Medical and Clinical Use
of National Instruments Products
National Instruments products are not designed with components and testing intended to ensure a level of reliability
suitable for use in treatment and diagnosis of humans. Applications of National Instruments products involving
medical or clinical treatment can create a potential for accidental injury caused by product failure, or by errors on
the part of the user or application designer. Any use or application of National Instruments products for or involving
medical or clinical treatment must be performed by properly trained and qualified medical personnel, and all
traditional medical safeguards, equipment, and procedures that are appropriate in the particular situation to prevent
serious injury or death should always continue to be used when National Instruments products are being used.
National Instruments products are NOT intended to be a substitute for any form of established process, procedure, or
equipment used to monitor or safeguard human health and safety in medical or clinical treatment.

FCC/DOC Radio Frequency Interference Compliance
This equipment generates and uses radio frequency energy and, if not installed and used in strict accordance with the
instructions in this manual, may cause interference to radio and television reception. This equipment has been tested
and found to comply with the following two regulatory agencies:
Federal Communications Commission
This device complies with Part 15 of the Federal Communications Commission (FCC) Rules for a Class A digital
device. Operation is subject to the following two conditions:
1. This device may not cause harmful interference in commercial environments.
2. This device must accept any interference received, including interference that may cause undesired operation.
Canadian Department of Communications
This device complies with the limits for radio noise emissions from digital apparatus set out in the Radio
Interference Regulations of the Canadian Department of Communications (DOC).
Le présent appareil numérique n’émet pas de bruits radioélectriques dépassant les limites applicables aux appareils
numériques de classe A prescrites dans le règlement sur le brouillage radioélectrique édicté par le ministère des
communications du Canada.
Instructions to Users
These regulations are designed to provide reasonable protection against harmful interference from the equipment to
radio reception in commercial areas. Operation of this equipment in a residential area is likely to cause harmful
interference, in which case the user will be required to correct the interference at his own expense.
There is no guarantee that interference will not occur in a particular installation. However, the chances of
interference are much less if the equipment is installed and used according to this instruction manual.
If the equipment does cause interference to radio or television reception, which can be determined by turning the
equipment on and off, one or more of the following suggestions may reduce or eliminate the problem.
• Operate the equipment and the receiver on different branches of your AC electrical system.
• Move the equipment away from the receiver with which it is interfering.
• Reorient or relocate the receiver’s antenna.
• Be sure that the equipment is plugged into a grounded outlet and that the grounding has not been defeated with
a cheater plug.
Notice to user: Changes or modifications not expressly approved by National Instruments could void the user’s
authority to operate the equipment under the FCC Rules.
If necessary, consult National Instruments or an experienced radio/television technician for additional suggestions.
The following booklet prepared by the FCC may also be helpful: How to Identify and Resolve Radio-TV
Interference Problems. This booklet is available from the U.S. Government Printing Office, Washington, DC
20402, Stock Number 004-000-00345-4.

© National Instruments Corporation vii VXI-AT2000/NI-VXI MS-DOS Getting Started
Contents
About This Manual............................................................................................................xi
Organization of This Manual...........................................................................................xi
Conventions Used in This Manual ..................................................................................xi
How to Use the Documentation Set.................................................................................xii
Related Documentation ...................................................................................................xii
Customer Communication...............................................................................................xiii
Chapter 1
Introduction..........................................................................................................................1-1
What Your Kit Should Contain......................................................................................1-2
Optional Equipment.......................................................................................................1-3
Optional Software..........................................................................................................1-4
Chapter 2
Hardware Configuration and Installation.................................................................2-1
Step 1. Unpack the AT-MXI and VXI-MXI..................................................................2-1
Step 2. Configure the AT-MXI Hardware.....................................................................2-2
Switch and Jumper Settings...............................................................................2-3
Base I/O Address Selection................................................................................2-3
Interrupt Level Selection....................................................................................2-6
DMA Channel Selection....................................................................................2-8
Master Mode Versus Slave Mode..........................................................2-8
Step 3. Install the AT-MXI Hardware ...........................................................................2-11
Step 4. Configure the VXI-MXI Hardware ...................................................................2-13
Front Panel Features...........................................................................................2-15
Removing the Metal Enclosure..........................................................................2-15
VXIbus Slot 0.....................................................................................................2-15
VMEbus BTO....................................................................................................2-18
VXI Logical Address.........................................................................................2-18
VMEbus Request Level Selection.....................................................................2-19
Step 5. Install the VXI-MXI Hardware..........................................................................2-21
Step 6. Connect the MXIbus Cable................................................................................2-22
Nonpolarized Cables..........................................................................................2-22
Polarized Cables.................................................................................................2-23
Chapter 3
NI-VXI Software Installation and Configuration...................................................3-1
NI-VXI Software Overview...........................................................................................3-1
Main Programs and Files...................................................................................3-1
Additional Programs and Files...........................................................................3-2
Installing the Software...................................................................................................3-5
Modifying the AUTOEXEC.BAT File..............................................................3-6
Configuring the NI-VXI Software.................................................................................3-6
Running VXIEDIT.............................................................................................3-7
Logical Address Configuration..........................................................................3-8
Bus Configuration..............................................................................................3-12

Contents
VXI-AT2000/NI-VXI MS-DOS Getting Started viii © National Instruments Corporation
Device Configuration.........................................................................................3-14
Exiting VXIEDIT and Reinitializing the Hardware ..........................................3-15
Developing Your Application Program.........................................................................3-16
Appendix A
Specifications........................................................................................................................A-1
Appendix B
Troubleshooting...................................................................................................................B-1
Problems with VXIINIT................................................................................................B-1
VXIINIT Error Messages...................................................................................B-1
VXIINIT Could Not Find the AT-MXI.................................................B-2
VXIINIT Could Not Find Specific Files................................................B-2
Error Writing Log File...........................................................................B-3
VXIINIT Causes System to Hang......................................................................B-3
Problems with RESMAN...............................................................................................B-4
Memory Area Used by Another Device ............................................................B-4
Memory Area Used by Expanded-Memory Manager or Emulator...................B-4
Problems with Mouse.....................................................................................................B-5
Problems with MXIbus Cable........................................................................................B-5
Appendix C
Customer Communication...............................................................................................C-1
Glossary......................................................................................................................Glossary-1

Contents
© National Instruments Corporation ixVXI-AT2000/NI-VXI MS-DOS Getting Started
Figures
Figure1-1. VXI-AT2000 Interface Kit...............................................................................1-1
Figure2-1. AT-MXI Parts Locator Diagram.......................................................................2-2
Figure2-2. Base I/O Address Switch Settings....................................................................2-4
Figure2-3. Board and MXIbus Interrupt Jumper Settings..................................................2-7
Figure2-4. DMA Channel Settings.....................................................................................2-10
Figure2-5. AT-MXI Installed in a Computer......................................................................2-12
Figure2-6. VXI-MXI Parts Locator Diagram.....................................................................2-13
Figure2-7. VXI-MXI with INTX Parts Locator Diagram..................................................2-14
Figure2-8. VXIbus Slot 0 Configuration............................................................................2-16
Figure2-9. VXIbus Non-Slot 0 Configuration....................................................................2-17
Figure2-10. Logical Address Selection................................................................................2-19
Figure2-11. VXI-MXI VMEbus Requester Jumper Settings...............................................2-20
Figure2-12. MXIbus Single-Ended Cable Configuration....................................................2-22
Figure2-13. MXIbus Dual-Ended Cable Configuration.......................................................2-23
Figure3-1. VXIEDIT Main Menu......................................................................................3-7
Figure3-2. AT-MXI Logical Address Configuration Editor..............................................3-8
Figure3-3. AT-MXI Bus Configuration Editor..................................................................3-12
Figure3-4. AT-MXI Device Configuration Editor.............................................................3-14
Tables
Table2-1. AT-MXI Factory Default Settings and Optional Configurations.....................2-3
Table2-2. Possible Base I/O Address Settings for the AT-MXI.......................................2-5
Table3-1. Logical Address Configuration Characteristics................................................3-9
Table3-2. Bus Configuration Characteristics....................................................................3-13
Table3-3. Device Configuration Characteristics...............................................................3-15

© National Instruments Corporation xi VXI-AT2000/NI-VXI MS-DOS Getting Started
About This Manual
This manual contains instructions for installing and configuring the National Instruments
VXI-AT2000 interface kit. This manual is meant to be used with the NI-VXI Software Reference
Manual for C (part number 320307-01), theNI-VXI Software Reference Manual for BASIC (part
number 320328-01), and the NI-VXI DOS Utilities Reference Manual (part number 320323-01).
Organization of This Manual
Getting Started with Your VXI-AT2000 and the NI-VXI Software for MS-DOS is organized as
follows:
• Chapter 1, Introduction, describes the VXI-AT2000 interface kit, contains a picture of the
VXI-AT2000 interface kit, lists the contents of your kit, and lists optional equipment and
software.
• Chapter 2, Hardware Configuration and Installation, contains the instructions to configure
and install the VXI-AT2000 interface kit.
• Chapter 3, NI-VXI Software Configuration and Installation, lists all the programs and files
located on the NI-VXI distribution diskettes, contains instructions for installing and
configuring the NI-VXI software for MS-DOS, and contains a description of the VXIEDIT
configuration editor.
• Appendix A, Specifications, lists various module specifications of the AT-MXI and
VXI-MXI, such as physical dimensions and power requirements.
• Appendix B, Troubleshooting, addresses certain problems you may encounter when using the
NI-VXI bus interface software on the AT-MXI platform.
• Appendix C, Customer Communication, contains forms you can use to request help from
National Instruments or to comment on our products and manuals.
• The Glossary contains an alphabetical list and description of terms used in this manual,
including abbreviations, acronyms, metric prefixes, and symbols.

About This Manual
VXI-AT2000/NI-VXI MS-DOS Getting Started xii © National Instruments Corporation
Conventions Used in This Manual
The following conventions are used to distinguish elements of text throughout this manual:
bold Bold text denotes menu items.
italic Italic text denotes emphasis, a cross reference, or an introduction to a key
concept.
bold italic Bold italic text denotes a note, caution, or warning.
monospace Text in this font denotes text or characters that are to be literally input
from the keyboard, the proper names of disk drives, paths, directories,
programs, subprograms, device names, filenames and extensions, and for
statements and comments taken from program code.
bold monospace Bold text in this font denotes the messages and responses that the
computer automatically prints to the screen.
<> Angle brackets enclose the name of a key on the keyboard–for example,
<Esc>.
Abbreviations, acronyms, metric prefixes, mnemonics, symbols, and terms are listed in the
Glossary.
How to Use the Documentation Set
We suggest that you begin by reading this manual to guide you through the installation and
configuration of the hardware and software. The software configuration requires that you first
complete the installation and configuration of the hardware.
When you are familiar with the material in this manual, you can begin to use the NI-VXI
Software Reference Manual for C. Chapter 1, Introduction to VXI, and Chapter 2, Introduction
to the NI-VXI Functions, present the concepts of VXI and prepare you for detailed explanations
of the NI-VXI functions. Study the descriptions of each function given in Chapters 3 through 13
to fully understand the purpose and syntax of each function. The NI-VXI Software Reference
Manual for BASIC covers the same material with BASIC syntax. Refer to the NI-VXI DOS
Utilities Reference Manual to learn more about the VIC and VXIEDIT programs. The
LabWindows VXI Library Reference Manual, part number 320318-01, explains how to install
and use the optional LabWindows VXI Library for the AT-MXI.

About This Manual
© National Instruments Corporation xiii VXI-AT2000/NI-VXI MS-DOS Getting Started
Related Documentation
The following documents contain information that you may find helpful as you read this manual:
•IEEE Standard for a Versatile Backplane Bus: VMEbus, ANSI/IEEE Standard 1014-1987
•Multisystem Extension Interface Bus Specification, Version 1.2 (part number 340007-01)
• VXI-1, VXIbus System Specification, Rev. 1.4, VXIbus Consortium (available from National
Instruments Corporation, part number 350083-01)
• VXI-6, VXIbus Mainframe Extender Specification, Rev. 1.0, VXIbus Consortium (available
from National Instruments Corporation, part number 340258-01)
•VXI-MXI User Manual (part number 320222-01)
Customer Communication
National Instruments wants to receive your comments on our products and manuals. We are
interested in the applications you develop using our products, and we want to help if you have
problems with them. To make it easy for you to contact us, this manual contains comment and
configuration forms for you to complete. These forms are in Appendix C, Customer
Communication, at the end of this manual.

© National Instruments Corporation 1-1 VXI-AT2000/NI-VXI MS-DOS Getting Started
Chapter 1
Introduction
This chapter describes the VXI-AT2000 interface kit, contains a picture of the VXI-AT2000
interface kit, lists the contents of your kit, and lists optional equipment and software.
The VXI-AT2000 is an interface kit that links any IBM Personal Computer AT or compatible
computer (hereafter referred to as the PC AT) directly to the VXIbus. A PC AT equipped with a
VXI-AT2000 can function as a VXI Commander and Resource Manager. The VXI-AT2000
makes the PC AT appear as though it were plugged directly into the VXI backplane as an
embedded CPU VXI module.
Figure 1-1 shows the VXI-AT2000 interface kit.
Figure 1-1. VXI-AT2000 Interface Kit
Art not available in PDF version of document.

Introduction Chapter 1
VXI-AT2000/NI-VXI MS-DOS Getting Started 1-2 © National Instruments Corporation
What Your Kit Should Contain
Your kit should contain the following components:
Component Part Number
AT-MXI Interface Board 180775-01
Standard VXI-MXI Interface Module 181045-01
or
Enhanced VXI-MXI Interface Module with INTX option 181045-02
3.5 in. NI-VXI Distribution Disks for the AT-MXI and 422178-48
and
MS-DOS 422179-48
and
5.25 in. NI-VXI Distribution Disks for the AT-MXI and 420178-48
and
MS-DOS 420179-48
2 m Type M1 MXIbus Cable * 180758-02
Getting Started with Your VXI-AT2000 and the NI-VXI
Software for MS-DOS 320219-01
NI-VXI DOS Utilities Reference Manual 320323-01
NI-VXI Software Reference Manual for BASIC 320328-01
NI-VXI Software Reference Manual for C 320307-01
* The 2 m Type M1 MXIbus cable is included in your kit unless you specified
otherwise in your order. You may have ordered your kit without this cable so
that you could order a different type or length of MXIbus cable. Refer to the
Optional Equipment section on the following page.
Make sure each of these items is in your kit. If any item is missing, contact National
Instruments.

Chapter 1 Introduction
© National Instruments Corporation 1-3 VXI-AT2000/NI-VXI MS-DOS Getting Started
Optional Equipment
Equipment Part Number
Type M1 MXIbus Cables
Straight Point-to-Point Connectors:
– 1 m 180758-01
– 2 m 180758-02
– 4 m 180758-04
– 8 m 180758-08
– 20 m 180758-20
Type M2 MXIbus Cables
Straight Point-to-Right Angle Daisy-Chain Connectors:
– 1 m 180760-01
– 2 m 180760-02
– 4 m 180760-04
– 8 m 180760-08
– 20 m 180760-20
Type M3 MXIbus Cables
Right Angle Point-to-Right Angle Daisy-Chain Connectors:
– 1 m 180761-01
– 2 m 180761-02
– 4 m 180761-04
– 8 m 180761-08
– 20 m 180761-20
MXIbus Terminating Pac (External) 180780-01
VXI-MXI Standard VXIbus Mainframe Extender Kit 776310-01
VXI-MXI Enhanced VXIbus Mainframe Extender Kit 776310-02
VME-MXI Standard VMEbus Chassis Extender Kit 776434-01
VME-MXI Enhanced VMEbus Chassis Extender Kit 776434-02

Introduction Chapter 1
VXI-AT2000/NI-VXI MS-DOS Getting Started 1-4 © National Instruments Corporation
Optional Software
If you want to use LabWindows with your VXI-AT2000 system, you can order either the
LabWindows for DOS, VXI Development System, or the LabWindows/CVI for Windows, VXI
Development System. If you want LabWindows/CVI, you must also order NI-VXI Windows
Software for the AT-MXI. The following table lists the subcomponents of the two kits.
Software Part Number
LabWindows for DOS, VXI Development System:
LabWindows for DOS Full Develoment System,
LabWindows for DOS VXI Libraries,
LabWindows for DOS VXI Instrument Library
776729-21
LabWindows/CVI for Windows, VXI Development System:
LabWindows/CVI for Windows Full Develoment System,
LabWindows/CVI for Windows VXI Libraries,
LabWindows/CVI for Windows VXI Instrument Library
776804-21
NI-VXI Windows Software for the AT-MXI
(required for LabWindows/CVI for Windows only) 776458-01
If you want to use LabVIEW with your VXI-AT2000, you must order NI-VXI Windows
Software for the AT-MXI and the LabVIEW for Windows VXI Development System.
Software Part Number
LabVIEW for Windows VXI Development System:
LabVIEW for Windows Full Development System,
LabVIEW for Windows VXI Library,
LabVIEW for Windows/Sun VXI Instrument Library
776674-21
NI-VXI Windows Software for the AT-MXI 776458-01

© National Instruments Corporation 2-1 VXI-AT2000/NI-VXI MS-DOS Getting Started
Chapter 2
Hardware Configuration and Installation
This chapter contains the instructions to configure and install the VXI-AT2000 interface kit. The
instructions are given in the order that you should perform them. A summary of the steps is as
follows:
1. Unpack the AT-MXI and VXI-MXI hardware.
2. Configure the AT-MXI hardware.
3. Install the AT-MXI hardware.
4. Configure the VXI-MXI hardware.
5. Install the VXI-MXI hardware.
6. Connect the MXIbus cable.
Step 1. Unpack the AT-MXI and VXI-MXI
Follow these steps when unpacking your AT-MXI board and VXI-MXI module:
1. Before attempting to configure or install the AT-MXI and VXI-MXI, inspect the shipping
container and its contents for damage. If damage appears to have been caused in shipment,
file a claim with the carrier. Retain the packing material for possible inspection and/or for
reshipment.
2. Verify that the pieces contained in the package you received match the kit parts list. Do not
remove the boards from their plastic bags at this point.
3. Your AT-MXI board and VXI-MXI module are shipped packaged in antistatic plastic bags to
prevent electrostatic damage. Some of the circuitry on the AT-MXI and VXI-MXI use
CMOS technology and can be damaged by electrostatic discharge. Before removing the
boards from their antistatic bags, touch the bags to a metal part of your computer chassis.
4. As you remove the AT-MXI and VXI-MXI from their bags, be sure to handle them only by
their edges. Avoid touching any of the IC components or connectors. Inspect them for loose
components or any other sign of damage. Notify National Instruments if either board
appears damaged in any way. Do not install equipment that appears to be damaged.

Hardware Configuration and Installation Chapter 2
VXI-AT2000/NI-VXI MS-DOS Getting Started 2-2 © National Instruments Corporation
Step 2. Configure the AT-MXI Hardware
Figure 2-1 shows the location of the AT-MXI configuration jumpers and switches.
Figure 2-1. AT-MXI Parts Locator Diagram
Switch and Jumper Settings
You can configure three options on the AT-MXI board:
• Base I/O address
• Interrupt levels
• DMA channels
Art not available in PDF version of document.

Chapter 2 Hardware Configuration and Installation
© National Instruments Corporation 2-3 VXI-AT2000/NI-VXI MS-DOS Getting Started
Table 2-1 shows the factory settings and optional configurations for the switches and jumpers on
the AT-MXI.
Table 2-1. AT-MXI Factory Default Settings and Optional Configurations
AT-MXI Default Optional
Base I/O Address (hex) 340 100 to 3E0, increments of 20 hex
Master DMA Channel 6 0, 1, 2, 3, 5, 6, 7, and Not Used
Slave DMA Channel 3 0, 1, 2, 3, 5, 6, 7, and Not Used
Board Interrupt Level 12 3, 4, 5, 6, 7, 9, 10, 11, 12, 14, and 15
MXIbus Interrupt Level 10 3, 4, 5, 6, 7, 9, 10, 11, 12, 14, 15,
and Not Used
The factory-configured settings of the base I/O address, the interrupt levels, and the Direct
Memory Access (DMA) channels are suitable for most computer systems. The following
sections describe under what conditions you would be required to change the configuration
switches and/or jumpers on the AT-MXI and how to make these changes.
Base I/O Address Selection
The base I/O address of the AT-MXI is the starting address of the AT-MXI configuration
registers in PC AT I/O space. The base I/O address is determined by the position of the five
switches at location U31, as shown in Figure 2-1. The switches are set at the factory for a base
I/O address of 340 hex. Because the AT-MXI requires 32 bytes of consecutive I/O space for
its internal registers, the factory configuration uses the I/O address space in the range of 340 to
35F hex.
Note: Check to determine that this space is not already used by other I/O interfaces
installed in your PC AT computer. If any equipment in your computer uses this I/O
address space, you must change either the base I/O address of the AT-MXI or the
I/O address space requirements of the other device. All PC AT devices must have a
unique partition of the system's I/O address space. If you change the base I/O
address of the AT-MXI, you must make a corresponding change to the AT-MXI
configuration software as described in the Configuring the NI-VXI Software section
of Chapter 3 of this manual.

Hardware Configuration and Installation Chapter 2
VXI-AT2000/NI-VXI MS-DOS Getting Started 2-4 © National Instruments Corporation
Each switch in U31 (1 through 5) corresponds to one of the PC AT address lines (A5 through
A9). The first switch (1) corresponds to address line A5, the next switch (2) corresponds to
address line A6, and so on. The five least significant bits of the address (A4 through A0) are
used by the AT-MXI to select the appropriate AT-MXI register and cannot be changed;
therefore, bits A4 through A0 are always zeros when determining the base I/O address.
To change the base I/O address of the AT-MXI, press the side markedOFF to select a binary
value of 1 for the corresponding address bit. Press the ON side of the switch to select a binary
value of 0 for the corresponding address bit. Refer to Table 2-2.
Figure 2-2 shows two possible switch settings.
OFF
54321
U31
Binary Hex
0
0
0
0
0
ON=0
ON=0
ON=0
OFF=1
ON=0
a. Switch Set to Base I/O Address hex 100
0
0
1
OFF
54321
U31
Binary Hex
0
0
0
0
0
ON=0
OFF=1
ON=0
OFF=1
OFF=1
b. Switch Set to Default Setting
(Base I/O Address hex 340)
0
4
3
Figure 2-2. Base I/O Address Switch Settings

Chapter 2 Hardware Configuration and Installation
© National Instruments Corporation 2-5 VXI-AT2000/NI-VXI MS-DOS Getting Started
Table 2-2 lists the 24 possible switch settings, the corresponding base I/O address, and the I/O
address space used for that setting. Notice that the base address settings that correspond to an
I/O address in the range from 0 to FF hex are not listed. These addresses are used by logic on the
PC AT motherboard and cannot be used by I/O adapter modules.
Table 2-2. Possible Base I/O Address Settings for the AT-MXI
Switch Setting Base I/O Address I/O Ports Used
A9 A8 A7 A6 A5 (hex) (hex)
0 1 0 0 0 100 100 - 11F
0 1 0 0 1 120 120 - 13F
0 1 0 1 0 140 140 - 15F
0 1 0 1 1 160 160 - 17F
0 1 1 0 0 180 180 - 19F
0 1 1 0 1 1A0 1A0 - 1BF
0 1 1 1 0 1C0 1C0 - 1DF
0 1 1 1 1 1E0 1E0 - 1FF
1 0 0 0 0 200 200 - 21F
1 0 0 0 1 220 220 - 23F
1 0 0 1 0 240 240 - 25F
1 0 0 1 1 260 260 - 27F
1 0 1 0 0 280 280 - 29F
1 0 1 0 1 2A0 2A0 - 2BF
1 0 1 1 0 2C0 2C0 - 2DF
1 0 1 1 1 2E0 2E0 - 2FF
1 1 0 0 0 300 300 - 31F
1 1 0 0 1 320 320 - 33F
1 1 0 1 0 340 (default) 340 - 35F
(continues)