National Instruments AT-MIO-16 User manual

© Copyright 1992, 1995 National Instruments Corporation.
All Rights Reserved.
AT-MIO-16
User Manual
Multifunction I/O Board for the PC/AT
February 1995 Edition
Part Number 320476-01

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Limited Warranty
The AT-MIO-16 is 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
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LabVIEW®, NI-DAQ®, and RTSI®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.

© National Instruments Corporation v AT-MIO-16 User Manual
Contents
About This Manual ..........................................................................................................ix
Organization of This Manual .......................................................................................ix
Conventions Used in This Manual...............................................................................x
Related Documentation................................................................................................x
Customer Communication ...........................................................................................x
Chapter 1
Introduction .......................................................................................................................1-1
About the AT-MIO-16.................................................................................................1-1
What You Need to Get Started ....................................................................................1-1
Software Programming Choices ..................................................................................1-2
LabVIEW and LabWindows Application Software ........................................1-2
NI-DAQ Driver Software.................................................................................1-3
Register-Level Programming...........................................................................1-5
Unpacking ....................................................................................................................1-5
Chapter 2
Configuration and Installation.....................................................................................2-1
Board Configuration ....................................................................................................2-1
AT Bus Interface..............................................................................................2-1
Base I/O Address Selection..................................................................2-3
DMA Channel Selection ......................................................................2-4
Interrupt Selection................................................................................2-5
Analog I/O Configuration ................................................................................2-6
Analog Input Configuration.................................................................2-8
Input Mode...............................................................................2-9
DIFF Input (Eight Channels, Factory Setting).............2-9
RSE Input (16 Channels) .............................................2-9
NRSE Input (16 Channels) ..........................................2-10
Analog Input Polarity and Range.............................................2-10
Considerations for Selecting Input Ranges..................2-11
Analog Output Configuration ..............................................................2-12
Analog Output Reference.........................................................2-13
Analog Output Polarity Selection ............................................2-14
Analog Output Data Coding ....................................................2-14
Digital I/O Configuration.................................................................................2-15
RTSI Bus Clock Selection ...............................................................................2-17
Hardware Installation...................................................................................................2-17
Chapter 3
Signal Connections ........................................................................................................... 3-1
I/O Connector...............................................................................................................3-1
Signal Descriptions ..........................................................................................3-3

Contents
AT-MIO-16 User Manual vi © National Instruments Corporation
Analog Input Signal Connections ........................................................3-4
Types of Signal Sources.......................................................................3-5
Floating Signal Sources ...........................................................3-6
Ground-Referenced Signal Sources.........................................3-6
Input Configurations ............................................................................3-6
Differential Connection Considerations
(DIFF Configuration)...............................................................3-7
Differential Connections for Grounded Signal Sources ..........3-8
Differential Connections for Floating Signal Sources .............3-8
Single-Ended Connection Considerations ...............................3-10
Single-Ended Connections for Floating Signal Sources
(RSE Configuration) ................................................................3-10
Single-Ended Connections for Grounded Signal Sources
(NRSE Configuration) .............................................................3-11
Common-Mode Signal Rejection Considerations....................3-11
Analog Output Signal Connections......................................................3-12
Digital I/O Signal Connections........................................................................3-13
Timing I/O Signals...........................................................................................3-15
RTSI Bus Signal Connections..........................................................................3-15
Power Connections ..........................................................................................3-16
Timing Connections.........................................................................................3-16
Data Acquisition Timing Connections.................................................3-16
General-Purpose Timing Signal Connections......................................3-19
Cabling and Field Wiring.............................................................................................3-25
Field Wiring Considerations ............................................................................3-25
Cabling Considerations....................................................................................3-26
Chapter 4
Calibration Procedures....................................................................................................4-1
Calibration Equipment Requirements..........................................................................4-1
Calibration Trimpots....................................................................................................4-2
Analog Input Calibration .............................................................................................4-3
Board Configuration ........................................................................................4-4
Bipolar Input Calibration Procedure................................................................4-4
1. Adjust the Amplifier Input Offset...................................................4-4
2. Adjust the ADC Input Offset ..........................................................4-4
3. Adjust the Analog Input Gain .........................................................4-5
Unipolar Input Calibration Procedure..............................................................4-5
1. Adjust the Amplifier Input Offset...................................................4-5
2. Adjust the ADC Input Offset ..........................................................4-6
3. Adjust the Analog Input Gain .........................................................4-6
Analog Output Calibration...........................................................................................4-6
Board Configuration ........................................................................................4-7
Bipolar Output Calibration Procedure .............................................................4-7
1. Adjust the Analog Output Offset ....................................................4-7
2. Adjust the Analog Output Gain ......................................................4-8
Unipolar Output Calibration Procedure ...........................................................4-8
1. Adjust the Analog Output Offset ....................................................4-8
2. Adjust the Analog Output Gain ......................................................4-9

Contents
© National Instruments Corporation vii AT-MIO-16 User Manual
Appendix A
Specifications.......................................................................................................................A-1
Appendix B
Revisions A through C Parts Locator Diagram ....................................................B-1
Appendix C
Customer Communication ............................................................................................C-1
Glossary......................................................................................................................Glossary-1
Index ................................................................................................................................Index-1
Figures
Figure 1-1. The Relationship between the Programming Environment, NI-DAQ,
and Your Hardware..........................................................................................1-4
Figure 2-1. AT-MIO-16 Parts Locator Diagram ................................................................2-2
Figure 2-2. Example Base I/O Address Switch Settings ....................................................2-3
Figure 2-3. Analog Input and Data Acquisition Circuitry Block Diagram ........................2-8
Figure 2-4. Analog Output Circuitry Block Diagram.........................................................2-13
Figure 2-5. Digital I/O Circuitry Block Diagram ...............................................................2-16
Figure 3-1. AT-MIO-16 I/O Connector Pin Assignments..................................................3-2
Figure 3-2. AT-MIO-16 Instrumentation Amplifier...........................................................3-5
Figure 3-3. Differential Input Connections for Grounded Signal Sources.........................3-8
Figure 3-4. Differential Input Connections for Floating Signal Sources............................ 3-9
Figure 3-5. Single-Ended Input Connections for Floating Signal Sources.........................3-10
Figure 3-6. Single-Ended Input Connections for Grounded Signal Sources......................3-11
Figure 3-7. Analog Output Connections.............................................................................3-13
Figure 3-8. Digital I/O Connections ...................................................................................3-14
Figure 3-9. RTSI Bus Interface Circuitry Block Diagram..................................................3-15
Figure 3-10. EXTSTROBE* Signal Timing.........................................................................3-17
Figure 3-11. EXTCONV* Signal Timing.............................................................................3-17
Figure 3-12. STARTTRIG* Signal Timing..........................................................................3-18
Figure 3-13. STOPTRIG Signal Timing...............................................................................3-18
Figure 3-14. Timing I/O Circuitry Block Diagram...............................................................3-19
Figure 3-15. Counter Block Diagram ...................................................................................3-20
Figure 3-16. Event-Counting Application with External Switch Gating..............................3-22
Figure 3-17. Frequency Measurement Application ..............................................................3-23
Figure 3-18. General-Purpose Timing Signals .....................................................................3-24
Figure 4-1. Calibration Trimpot Location Diagram ...........................................................4-2
Figure B-1. Revisions A through C Parts Locator Diagram ...............................................B-2

Contents
AT-MIO-16 User Manual viii © National Instruments Corporation
Tables
Table 2-1. AT Bus Interface Factory-Default Settings .....................................................2-1
Table 2-2. Switch Settings with Corresponding Base I/O Address and
Base I/O Address Space...................................................................................2-4
Table 2-3. DMA Jumper Settings......................................................................................2-5
Table 2-4. Interrupt Jumper Settings.................................................................................2-5
Table 2-5. Analog I/O Jumper Settings Quick Reference.................................................2-6
Table 2-6. DIFF Input Configuration (Factory Setting)....................................................2-9
Table 2-7. RSE Input Configuration .................................................................................2-10
Table 2-8. NRSE Input Configuration...............................................................................2-10
Table 2-9. Configurations for Input Range and Input Polarity .........................................2-11
Table 2-10. Actual Range and Measurement Precision Versus Input Range
Selection and Gain ...........................................................................................2-12
Table 2-11. Internal and External Reference Selection.......................................................2-14
Table 2-12. Analog Output Polarity and Data Mode Configuration...................................2-15
Table 2-13. Output Range Selection and Precision.............................................................2-15
Table 2-14. Configurations for RTSI Bus Clock Selection.................................................2-17
Table 3-1. Recommended Input Configurations for Ground-Referenced
and Floating Signal Sources.............................................................................3-6
Table 4-1. Voltage Values for Calculating Offset Error ...................................................4-3

© National Instruments Corporation ix AT-MIO-16 User Manual
About This Manual
This manual describes the electrical and mechanical aspects of the AT-MIO-16 and contains
information concerning its operation and programming. The AT-MIO-16 is a high-performance
multifunction analog, digital, and timing I/O board, and is a member of the National Instruments
AT Series of expansion boards for the IBM PC AT and compatible computers. The AT-MIO-16
contains a 12-bit ADC with up to 16 analog inputs, two 12-bit DACs with voltage outputs, eight
lines of TTL-compatible digital I/O, and three 16-bit counter/timer channels for timing I/O. If
you need additional analog inputs, you can use the AMUX-64T multiplexer board, which is a
four-to-one multiplexer that can process 64 single-ended inputs. You can cascade up to four
AMUX-64Ts to obtain 256 single-ended inputs.
Organization of This Manual
The AT-MIO-16 User Manual is organized as follows:
• Chapter 1, Introduction, describes the AT-MIO-16; lists the contents of your AT-MIO-16 kit,
the optional software, and optional equipment; and explains how to unpack the AT-MIO-16.
• Chapter 2, Configuration and Installation, describes how to configure the AT-MIO-16
jumpers and how to install the AT-MIO-16 board into the PC.
• Chapter 3, Signal Connections, describes the signal connections to the AT-MIO-16 board,
and cable wiring.
• Chapter 4, Calibration Procedures, discusses the calibration procedures for the AT-MIO-16
analog input and analog output circuitry.
• Appendix A, Specifications, lists the specifications for the AT-MIO-16.
• Appendix B, Revisions A through C Parts Locator Diagram, contains the parts locator
diagram for revisions A through C of the AT-MIO-16 board.
• Appendix C, Customer Communication, contains forms you can use to request help from
National Instruments or to comment on our products.
• The Glossary contains an alphabetical list and description of terms used in this manual,
including acronyms, abbreviations, metric prefixes, mnemonics, and symbols.
• The Index alphabetically lists topics covered in this manual, including the page where you
can find the topic.

About This Manual
AT-MIO-16 User Manual x © National Instruments Corporation
Conventions Used in This Manual
The following conventions are used in this manual.
bold italic Bold italic text denotes a note, caution, or warning.
italic Italic text denotes emphasis, a cross reference, or an introduction to a key
concept.
NI-DAQ NI-DAQ is used throughout this manual to refer to the NI-DAQ software
for PC compatibles unless otherwise noted.
PC PC refers to the IBM PC AT and compatible computers.
Abbreviations, acronyms, metric prefixes, mnemonics, symbols, and terms are listed in the
Glossary.
Related Documentation
The following document contains information that you may find helpful as you read this manual:
•IBM Personal Computer AT Technical Reference manual
You may also want to consult the following Advanced Micro Devices manual if you plan to
program the Am9513A counter/timer used on the AT-MIO-16:
•Am9513A/Am9513 System Timing Controller technical manual
National Instruments offers a register-level programmer manual at no charge to customers who
are not using National Instruments software:
•AT-MIO-16 Register-Level Programmer Manual
If you are using NI-DAQ, LabVIEW, or LabWindows®, you should not need the register-level
programmer manual. Using NI-DAQ, LabVIEW, or LabWindows is quicker and easier than and
as flexible as using the low-level programming described in the register-level programmer
manual. Refer to Software Programming Choices in Chapter 1, Introduction, of this manual if
you need more information about your programming options.
If you are not using National Instruments software, you can request the register-level
programmer manual by mailing or faxing the Register-Level Programmer Manual Request Form
at the back of this manual to National Instruments.
Customer Communication
National Instruments wants to receive your comments on our products and manuals. We are
interested in the applications you develop with 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 AT-MIO-16 User Manual
Chapter 1
Introduction
This chapter describes the AT-MIO-16; lists the contents of your AT-MIO-16 kit; describes the
optional software and optional equipment; and explains how to unpack the AT-MIO-16.
About the AT-MIO-16
Congratulations on your purchase of the National Instruments AT-MIO-16. The AT-MIO-16 is a
high-performance, software-configurable 12-bit DAQ board for laboratory, test and
measurement, and data acquisition and control applications. The board performs high-accuracy
measurements with high-speed settling to 12 bits, noise as low as 0.1 LSBrms, and a typical
DNL of ±0.5 LSB. Because of its FIFOs and dual-channel DMA, the AT-MIO-16 can achieve
high performance, even when used in environments that may have long interrupt latencies such
as Windows.
A common problem with DAQ boards is that you cannot easily synchronize several
measurement functions to a common trigger or timing event. The AT-MIO-16 has the Real-
Time System Integration (RTSI) bus to solve this problem. The RTSIbus consists of our custom
RTSI bus interface chip and a ribbon cable to route timing and trigger signals between several
functions on one or DAQ boards in your PC.
The AT-MIO-16 can interface to the Signal Conditioning eXtensions for Instrumentation (SCXI)
system so that you can acquire over 3,000 analog signals from thermocouples, RTDs, strain
gauges, voltage sources, and current sources. You can also acquire or generate digital signals for
communication and control. SCXI is the instrumentation front-end for plug-in DAQ boards.
What You Need to Get Started
Two versions of the AT-MIO-16 are available–one version for each of two gain ranges. The
AT-MIO-16L (L stands for low-level signals) has software-programmable gain settings of 1, 10,
100, and 500 for low-level analog input signals. The AT-MIO-16H (H stands for high-level
signals) has software-programmable gain settings of 1, 2, 4, and 8 for high-level analog input
signals. The AT-MIO-16(L/H)-9 contains an ADC with a 9 µs conversion time. The
AT-MIO-16(L/H)-9 is capable of data acquisition rates of up to 100 kHz.
To set up and use your AT-MIO-16 board, you will need the following:
An AT-MIO-16 board
AT-MIO-16 User Manual

Introduction Chapter 1
AT-MIO-16 User Manual 1-2 © National Instruments Corporation
Either of the following software:
NI-DAQ software for PC compatibles, with manuals
LabVIEW for Windows, LabWindows for DOS, or LabWindows/CVI for Windows,
with manuals
Your computer
Detailed specifications of the AT-MIO-16 are listed in Appendix A, Specifications.
Software Programming Choices
There are four options to choose from when programming your National Instruments plug-in
DAQ and SCXI hardware. You can use LabVIEW, LabWindows, NI-DAQ, or register-level
programming software.
The AT-MIO-16 works with LabVIEW for Windows, LabWindows for DOS, LabWindows/CVI
for Windows, and NI-DAQ for PC compatibles.
LabVIEW and LabWindows Application Software
LabVIEW and LabWindows are innovative program development software packages for data
acquisition and control applications. LabVIEW uses graphical programming, whereas
LabWindows enhances traditional programming languages. Both packages include extensive
libraries for data acquisition, instrument control, data analysis, and graphical data presentation.
LabVIEW currently runs on four different platforms—AT/MC/EISA computers running
Microsoft Windows, NEC 9800 computers running Microsoft Windows, the Macintosh platform,
and the Sun SPARCstation platform. LabVIEW features interactive graphics, a state-of-the-art
user interface, and a powerful graphical programming language. The LabVIEW Data
Acquisition VI Library, a series of VIs for using LabVIEW with National Instruments boards, is
included with LabVIEW. The LabVIEW Data Acquisition VI Libraries are functionally
equivalent to the NI-DAQ software.
LabWindows has two versions—LabWindows for DOS is for use on PCs running DOS, and
LabWindows/CVI is for use on PCs running Windows and Sun SPARCstations.
LabWindows/CVI features interactive graphics, a state-of-the-art user interface, and uses the
ANSI standard C programming language. The LabWindows Data Acquisition Library, a series
of functions for using LabWindows with National Instruments boards, is included with
LabWindows for DOS and LabWindows/CVI. The LabWindows Data Acquisition libraries are
functionally equivalent to the NI-DAQ software.
Using LabVIEW or LabWindows software will greatly diminish the development time for your
data acquisition and control application.

Chapter 1 Introduction
© National Instruments Corporation 1-3 AT-MIO-16 User Manual
NI-DAQ Driver Software
The NI-DAQ driver software is included at no charge with all National Instruments DAQ
hardware. NI-DAQ is not packaged with SCXI or accessory products, except for the SCXI-1200.
NI-DAQ has an extensive library of functions that you can call from your application
programming environment. These functions include routines for analog input (A/D conversion),
buffered data acquisition (high-speed A/D conversion), analog output (D/A conversion),
waveform generation, digital I/O, counter/timer operations, SCXI, RTSI, self-calibration,
messaging, and acquiring data to extended memory.
NI-DAQ has both high-level DAQ I/O functions for maximum ease of use and low-level data
acquisition I/O functions for maximum flexibility and performance. Examples of high-level
functions are streaming data to disk or acquiring a certain number of data points. An example of
a low-level function is writing directly to registers on the data acquisition device. NI-DAQ does
not sacrifice the performance of National Instruments data acquisition devices because it lets
multiple devices operate at their peak performance—up to 500 kS/s on ISA computers and up to
1 MS/s on EISA computers.
NI-DAQ includes a Buffer and Data Manager that uses sophisticated techniques for handling
and managing data acquisition buffers so that you can simultaneously acquire and process data.
NI-DAQ functions for the AT-MIO-16 can transfer data using interrupts or software polling.
With the NI-DAQ Resource Manager, you can simultaneously use several functions and several
DAQ devices. The Resource Manager prevents multiple-device contention over DMA channels,
interrupt levels, and RTSI channels.
NI-DAQ can send event-driven messages to DOS, Windows, or Windows NT applications
whenever a user-specified event occurs. Thus, polling is eliminated and you can develop event-
driven data acquisition applications. An example of a NI-DAQ user event is when a specified
digital I/O pattern is matched.
NI-DAQ also internally addresses many of the complex issues between the computer and the
DAQ hardware such as programming interrupts and DMA controllers. NI-DAQ maintains a
consistent software interface among its different versions so that you can change platforms with
minimal modifications to your code. Figure 1-1 illustrates the relationship between NI-DAQ and
LabVIEW and LabWindows. You can see that the data acquisition parts of LabVIEW and
LabWindows are functionally equivalent to the NI-DAQ software.

Introduction Chapter 1
AT-MIO-16 User Manual 1-4 © National Instruments Corporation
LabWindows
(PC or 
Sun SPARCstation)
LabVIEW 
(PC, Macintosh, or 
Sun SPARCstation)
Conventional 
Programming 
Environment 
(PC, Macintosh, or 
Sun SPARCstation)

NI-DAQ
Driver Software
DAQ or
SCXI Hardware
Personal 
Computer
or
Workstation
Figure 1-1. The Relationship between the Programming Environment,
NI-DAQ, and Your Hardware
The National Instruments PC, AT, MC, EISA, DAQCard, and DAQPad Series DAQ hardware
and the SCXI-1200 are packaged with NI-DAQ software for PC compatibles. NI-DAQ software
for PC compatibles comes with language interfaces for Professional BASIC, QuickBASIC,
Visual Basic, Borland Turbo Pascal, Turbo C++, Borland C++, Microsoft Visual C++, and
Microsoft C for DOS; and Visual Basic, Turbo Pascal, Microsoft C with SDK, Microsoft Visual
C++, and Borland C++ for Windows; and Microsoft Visual C++ for Windows NT. You can use
your AT-MIO-16, together with other PC, AT, MC, EISA, DAQCard, and DAQPad Series DAQ
and SCXI hardware, with NI-DAQ software for PC compatibles.
The National Instruments NB Series DAQ boards are packaged with NI-DAQ software for
Macintosh. NI-DAQ software for Macintosh comes with language interfaces for MPW C,
THINK C, Pascal, and Microsoft QuickBASIC. Any language that uses Device Manager
Toolbox calls can access NI-DAQ software for Macintosh. You can use NB Series DAQ boards
and SCXI hardware with NI-DAQ software for Macintosh.
The National Instruments SB Series DAQ boards are packaged with NI-DAQ software for Sun,
which comes with a language interface for ANSI C.

Chapter 1 Introduction
© National Instruments Corporation 1-5 AT-MIO-16 User Manual
Register-Level Programming
The final option for programming any National Instruments DAQ hardware is to write register-
level software. Writing register-level programming software can be very time consuming and
inefficient, and is not recommended for most users. The only users who should consider writing
register-level software should meet at least one of the following criteria:
• National Instruments does not support your operating system or programming language.
• You are an experienced register-level programmer who is more comfortable writing your
own register-level software.
Even if you are an experienced register-level programmer, consider using NI-DAQ, LabVIEW,
or LabWindows to program your National Instruments DAQ hardware. Using the NI-DAQ,
LabVIEW, or LabWindows software is easier than, is as flexible as, and can save weeks of
development time.
The AT-MIO-16 User Manual and your software manuals contains complete instructions for
programming your AT-MIO-16 board with NI-DAQ, LabVIEW, or LabWindows. If you are
using NI-DAQ, LabVIEW, or LabWindows to control your board, you should not need the
register-level programmer manual.
The AT-MIO-16 Register-Level Programmer Manual contains low-level programming details,
such as register maps, bit descriptions, and register programming hints, that you will need only
for register-level programming. If you want to obtain the register-level programmer manual,
please fill out the Register-Level Programmer Manual Request Form at the end of this manual
and send it to National Instruments.
Unpacking
Your AT-MIO-16 board is shipped in an antistatic package to prevent electrostatic damage to the
board. Electrostatic discharge can damage several components on the board. To avoid such
damage in handling the board, take the following precautions:
• Ground yourself via a grounding strap or by holding a grounded object.
• Touch the antistatic package to a metal part of your computer chassis before removing the
board from the package.
• Remove the board from the package and inspect the board for loose components or any other
sign of damage. Notify National Instruments if the board appears damaged in any way. Do
not install a damaged board into your computer.
•Never touch the exposed pin of connectors.

© National Instruments Corporation 2-1 AT-MIO-16 User Manual
Chapter 2
Configuration and Installation
This chapter describes how to configure the AT-MIO-16 jumpers and how to install the
AT-MIO-16 board into the PC.
Board Configuration
The AT-MIO-16 contains 13 jumpers and one DIP switch to configure the AT bus interface and
analog I/O settings. The DIP switch is for setting the base I/O address. Two jumpers are
interrupt channel and DMA selectors. The remaining 11 jumpers change the analog input and
analog output circuitry. The parts locator diagram in Figure 2-1 shows the user-configurable
jumpers. Jumpers W1, W4, W6, and W9 configure the analog input circuitry. Jumpers W2, W3,
W7, W8, W10, and W11 configure the analog output circuitry. Jumper W5 selects the clock
signal the Am9513A counter/timer uses and selects the clock pin on the RTSI bus. Jumpers W12
and W13 select the DMA channel and the interrupt level, respectively.
AT Bus Interface
The AT-MIO-16 is configured at the factory to a base I/O address of hex 220, to use DMA
channels 6 and 7, and to use interrupt level 10. These settings, as shown in Table 2-1, are
suitable for most systems. If your system, however, has other hardware at this base I/O address,
DMA channel, or interrupt level, you will need to change these settings on the other hardware or
on the AT-MIO-16 as described in the following pages.
Table 2-1. AT Bus Interface Factory-Default Settings
AT-MIO-16 Board Default Setting Hardware Implementation
Base I/O address
U61
Hex 220
Range: hex 220 to hex 23F
U61
12345
A9 A8 A7 A6 A5
Address space 32 bytes (hex 20)
DMA channel
W12
DMA 1 = DMA channel 6
DMA 2 = DMA channel 7
R7
A7
R6
A6
R5
A5
W12
1DMA 2
Interrupt level
W13
Interrupt level 10 selected
3456791011121415
IRQ
W13

Chapter 2 Configuration and Installation
© National Instruments Corporation 2-3 AT-MIO-16 User Manual
Note: The parts locator diagram shown in Figure 2-1 is for revision D and subsequent
revisions of the AT-MIO-16 board. See Appendix B, Revisions A through C Parts
Locator Diagram, for earlier revisions of the AT-MIO-16 board. The remainder of this
chapter applies to all revisions of the AT-MIO-16 board.
In the configuration illustrations throughout this chapter, the black bars on the jumper diagrams
indicate where to place jumpers. On the switch diagrams, the shaded portion indicates the side of
the switch that is pressed down.
Base I/O Address Selection
The switches at position U61 determine the base I/O address for the AT-MIO-16, as shown in
Figure 2-1. Each switch in U61 corresponds to one of the address lines A9 through A5. Press
the side marked OFF to select a binary value of 1 for the corresponding address bit. Press the
other side of the switch to select a binary value of 0 for the corresponding address bit. Figure 2-2
shows two possible switch settings.
Note: Verify that other equipment installed in your computer does not already occupy the
AT-MIO-16 address space. If any equipment in your computer uses this base I/O
address space, you must change the base I/O address of either the AT-MIO-16 or that
of the other device. If you change the AT-MIO-16 base I/O address, you must make
a corresponding change to any software you use with the AT-MIO-16. For more
information about the I/O address of your PC AT, refer to the technical reference
manual for your computer.
This side down for 0 This side down for 0
U61
12345
A9 A8 A7 A6 A5
U61
12345
A9 A8 A7 A6 A5
This side down for 1 This side down for 1
a. Switches Set to Base I/O
Address of Hex 000 b. Switches Set to Base I/O Address of Hex
220 (Factory Setting)
Figure 2-2. Example Base I/O Address Switch Settings
To change the base I/O address, remove the plastic cover on U61; press each switch to the
desired position; check each switch to make sure the switch is pressed down all the way; and
replace the plastic cover. Make a note of the new AT-MIO-16 base I/O address on the
configuration form in Appendix C, Customer Communication, to use when configuring the
software you are using with the AT-MIO-16. Table 2-2 lists the possible switch settings, the
corresponding base I/O address, and the base I/O address space for each setting.

Configuration and Installation Chapter 2
AT-MIO-16 User Manual 2-4 © National Instruments Corporation
Table 2-2. Switch Settings with Corresponding Base I/O Address and Base I/O Address Space
Switch Setting Base I/O Address Base I/O Address
A9 A8 A7 A6 A5 (hex) Space Used (hex)
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 0 340 340-35F
1 1 0 1 1 360 360-37F
1 1 1 0 0 380 380-39F
1 1 1 0 1 3A0 3A0-3BF
1 1 1 1 0 3C0 3C0-3DF
1 1 1 1 1 3E0 3E0-3FF
Note: Base I/O address values hex 000 through 0FF are reserved for
system use. Base I/O address values hex 100 through 3FF are
available on the I/O channel.
DMA Channel Selection
The AT-MIO-16 uses the DMA channel you select with the jumpers on W12 as shown in
Figure 2-1. The AT-MIO-16 is set at the factory to use DMA channels 6 and 7. Verify that
equipment already installed in your computer does not also use these DMA channels. If any
device uses DMA channel 6 or 7, change or disable the DMA channel or channels of either the
AT-MIO-16 or the other device. The AT-MIO-16 hardware supports DMA channels 5, 6, and 7.
Notice that these are the three 16-bit channels on the PC AT I/O channel. The AT-MIO-16 does
not use and cannot be configured to use the 8-bit DMA channels on the PC AT I/O channel.
You must install two jumpers on W12 to select a DMA channel. The DMA Acknowledge lines
(A- prefix is printed on the board) and the DMA Request lines (R- prefix is printed on the board)
that you select must have the same number suffix (5, 6, or 7) for proper operation. When you
enable two DMA channels, the driver software has the option of using dual DMA mode, which
may improve performance in high-rate data acquisition. However, data acquisition can operate
properly with one or both DMA channels disabled. Disabling DMA 2 or disabling both DMA
channels may be necessary if no more DMA channels are available on your system. If two
AT-MIO-16s are installed in the same computer, for instance, you must disable DMA 2 on one
of the boards. The left two columns of W12 are for DMA 1, which is referred to as DMA A in
National Instruments software. The right two columns of W12 are for DMA 2, which is referred