National Instruments NI-488.2M User manual

© Copyright 1993, 1995 National Instruments Corporation.
All Rights Reserved.
NI-488.2M™
Software Reference Manual
for OS/2
January 1995 Edition
Part Number 370950A-01

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© National Instruments Corp. v NI-488.2M SRM for OS/2
Contents
About This Manual ..........................................................................xi
Organization of This Manual......................................................xi
Conventions Used in This Manual.............................................xii
How to Use This Manual Set......................................................xiv
Related Documentation ..............................................................xv
Customer Communication..........................................................xv
Chapter 1
NI-488.2M Software Description................................................1-1
The NI-488.2M Software Package.............................................1-1
NI-488.2M Driver and Driver Utilities ........................1-1
Language Files.............................................................1-2
Example Program Files................................................1-2
API-Related Files.........................................................1-3
How the NI-488.2M Software Works with OS/2.......................1-4
GPIB Overview ..........................................................................1-5
The IEEE 488 Standard and GPIB...............................1-5
Talkers, Listeners, and Controllers ..............................1-5
Controller-In-Charge and System Controller...............1-6
Sending Messages Across the GPIB............................1-6
Data Lines......................................................1-6
Handshake Lines............................................1-6
Interface Management Lines .........................1-7
Setting Up and Configuring Your System...................1-7
Controlling More Than One Board..............................1-9
Chapter 2
Application Examples.....................................................................2-1
Example 1: Basic Communication ............................................2-2
Example 2: Clearing and Triggering Devices...........................2-4
Example 3: Asynchronous I/O...................................................2-6
Example 4: End-of-String Mode...............................................2-8
Example 5: Service Requests.....................................................2-10
Example 6: Basic Communication with IEEE 488.2
Compliant Devices.................................................2-14
Example 7: Serial Polls Using NI-488.2 Routines ....................2-16
Example 8: Parallel Polls...........................................................2-18
Example 9: Non-Controller Example........................................2-21

Contents
NI-488.2M SRM for OS/2 vi © National Instruments Corp.
Chapter 3
Developing Your Application.......................................................3-1
Choosing a Programming Method..............................................3-1
Using the NI-488.2 Language Interface.......................3-1
Using NI-488 Functions: One Device for
Each Board.....................................................3-2
NI-488 Device-Level Functions......3-2
NI-488 Board-Level Functions .......3-3
Using NI-488.2 Routines: Multiple Boards
and/or Multiple Devices.................................3-3
Using the OS/2 API Interface.......................................3-4
Checking Status with Global Variables......................................3-4
Status Word—ibsta ......................................................3-4
Error Variable—iberr...................................................3-6
Count Variables—ibcnt and ibcntl...............................3-6
Using ibic to Communicate with Devices..................................3-7
Writing Your NI-488 Application..............................................3-7
Items to Include............................................................3-7
NI-488 Program Shell ..................................................3-8
General Program Steps and Examples.........................3-9
Writing Your NI-488.2 Application...........................................3-13
Items to Include............................................................3-13
NI-488.2 Program Shell...............................................3-14
General Program Steps and Examples.........................3-15
Compiling and Linking Your Program.......................................3-20
32-Bit C Applications...................................................3-20
16-Bit C Applications...................................................3-21
Running Your Application Program...........................................3-21
Chapter 4
Debugging Your Application.......................................................4-1
Running ibtest.............................................................................4-1
Presence Test of Driver................................................4-1
Presence Test of GPIB Board.......................................4-2
Incorrect Interrupt Level ..............................................4-2
GPIB Cables Connected...............................................4-2
Debugging with the Global Status Variables .............................4-3
Debugging with ibic...................................................................4-3
GPIB Error Codes.......................................................................4-3
Configuration Errors...................................................................4-4
Reconfiguring the NI-488.2M Software ......................4-5
Timing Errors .............................................................................4-5

Contents
© National Instruments Corp. vii NI-488.2M SRM for OS/2
Communication Errors ...............................................................4-6
Repeat Addressing .......................................................4-6
Termination Method.....................................................4-6
Chapter 5
ibic—Interface Bus Interactive Control Utility....................5-1
Overview.....................................................................................5-1
Starting ibic.................................................................................5-1
Exiting ibic .................................................................................5-2
ibic Syntax..................................................................................5-2
Adding End-of-String Characters...............................................5-9
Status Word Return.....................................................................5-9
Error Codes Return.....................................................................5-10
Count Return...............................................................................5-10
Common NI-488.2 Routines in ibic ...........................................5-11
Send..............................................................................5-11
Receive.........................................................................5-12
Common NI-488 Functions in ibic.............................................5-13
ibfind ............................................................................5-13
ibdev.............................................................................5-13
ibwrt .............................................................................5-16
ibrd ...............................................................................5-17
Auxiliary Functions....................................................................5-18
Set (Select Device or Board)........................................5-19
Help (Display Help Information).................................5-20
! (Repeat Previous Function) .......................................5-21
- (Turn OFF Display) and + (Turn ON Display) .........5-21
n* (Repeat Function n Times)......................................5-22
$ (Execute Indirect File)...............................................5-23
Print (Display the ASCII String)..................................5-24
ibic Examples .............................................................................5-24
NI-488.2 Routines Example.........................................5-24
NI-488 Device Functions Example..............................5-28
NI-488 Board Functions Example ...............................5-31
Chapter 6
GPIB Programming Techniques................................................6-1
Termination of Data Transfers ...................................................6-1
Waiting for GPIB Conditions.....................................................6-2
Device-Level Calls and Bus Management.................................6-2
Serial Polling ..............................................................................6-3
Service Requests from IEEE 488 Devices...................6-3
Service Requests from IEEE 488.2 Devices................6-4

Contents
NI-488.2M SRM for OS/2 viii © National Instruments Corp.
Automatic Serial Polling..............................................6-4
Autopolling and the Stuck SRQ State ...........6-5
Autopolling and Interrupts.............................6-5
SRQ and Serial Polling with NI-488 Device
Functions......................................................................6-6
SRQ and Serial Polling with NI-488.2 Routines .........6-6
Example 1 ......................................................6-7
Example 2 ......................................................6-8
Parallel Polling ...........................................................................6-9
Implementing a Parallel Poll........................................6-9
Parallel Polling with NI-488.2 Routines........6-9
Parallel Polling with NI-488 Functions.........6-10
Chapter 7
ibconf—Interface Bus Configuration Utility.........................7-1
Overview.....................................................................................7-1
Starting ibconf ............................................................................7-1
Levels of ibconf..........................................................................7-2
Input Selection Level ...................................................7-2
Map Level ....................................................................7-4
Device Map of the Boards.............................7-5
Help................................................................7-5
Rename ..........................................................7-5
(Dis)connect...................................................7-6
Edit.................................................................7-6
Exit.................................................................7-6
Description Level.........................................................7-7
Change Characteristics...................................7-8
Next Board/Device.........................................7-8
Help................................................................7-8
Reset Value....................................................7-8
Return to Map................................................7-8
Output Selection Level.................................................7-9
Board and Device Configuration Options ..................................7-9
Primary GPIB Address.................................................7-10
Secondary GPIB Address.............................................7-10
Timeout Setting............................................................7-10
Terminate Read on EOS...............................................7-11
Set EOI with EOS on Write.........................................7-11
Type of Compare on EOS............................................7-11
EOS Byte......................................................................7-11
Send EOI at End of Write ............................................7-12
GPIB-Specific Errors...................................................7-12

Contents
© National Instruments Corp. ix NI-488.2M SRM for OS/2
System Controller.........................................................7-12
Assert REN when SC...................................................7-12
Enable Auto Serial Polling...........................................7-13
Enable CIC Protocol.....................................................7-13
Bus Timing...................................................................7-13
Parallel Poll Duration...................................................7-13
Use This GPIB Interface ..............................................7-14
Base I/O Address .........................................................7-14
DMA Channel ..............................................................7-14
Interrupt Jumper Setting...............................................7-15
DMA Transfer Mode ...................................................7-15
Serial Poll Timeout.......................................................7-15
Enable Repeat Addressing ...........................................7-15
Default Configurations in ibconf................................................7-16
Exiting ibconf.............................................................................7-17
Appendix A
Status Word Conditions.................................................................A-1
Appendix B
Error Codes and Solutions............................................................B-1
Appendix C
Customer Communication............................................................C-1
Glossary.................................................................................................G-1
Index.......................................................................................................I-1

Contents
NI-488.2M SRM for OS/2 x © National Instruments Corp.
Figures
Figure 1-1. How the NI-488.2M Software Works with OS/2 ............1-4
Figure 1-2. Linear and Star System Configuration.............................1-8
Figure 1-3. Example of Multiboard System Setup.............................1-9
Figure 2-1. Program Flowchart for Example 1...................................2-3
Figure 2-2. Program Flowchart for Example 2...................................2-5
Figure 2-3. Program Flowchart for Example 3...................................2-7
Figure 2-4. Program Flowchart for Example 4...................................2-9
Figure 2-5. Program Flowchart for Example 5...................................2-12
Figure 2-6. Program Flowchart for Example 6...................................2-15
Figure 2-7. Program Flowchart for Example 7...................................2-17
Figure 2-8. Program Flowchart for Example 8...................................2-20
Figure 2-9. Program Flowchart for Example 9...................................2-22
Figure 3-1. General Program Shell Using NI-488 Device
Functions..........................................................................3-8
Figure 3-2. General Program Shell Using NI-488.2 Routines ...........3-14
Figure 7-1. Input Selection Level of ibconf .......................................7-2
Figure 7-2. Map Level of ibconf ........................................................7-4
Figure 7-3. Description Level of ibconf.............................................7-7
Figure 7-4. Output Selection Level of ibconf.....................................7-9
Tables
Table 1-1. GPIB Handshake Lines....................................................1-6
Table 1-2. GPIB Interface Management Lines .................................1-7
Table 3-1. Status Word (ibsta) Layout..............................................3-5
Table 4-1. GPIB Error Codes............................................................4-4
Table 5-1. Syntax for NI-488 Functions in ibic ................................5-3
Table 5-2. Syntax for NI-488.2 Routines in ibic...............................5-5
Table 5-3. Auxiliary Functions in ibic ..............................................5-18
Table A-1. Status Word (ibsta) Layout..............................................A-1
Table B-1. GPIB Error Codes............................................................B-1

© National Instruments Corp. xi NI-488.2M SRM for OS/2
About This Manual
This manual describes the features and functions of the NI-488.2M software for
OS/2. The NI-488.2M software package is meant to be used with OS/2 (IBM
Operating System/2) version 2.0 or higher. This manual assumes that you are
already familiar with the OS/2 system.
Organization of This Manual
This manual is organized as follows:
• Chapter 1, NI-488.2M Software Description, describes the NI-488.2M
software package and explains how the software works with your OS/2
system.
• Chapter 2, Application Examples, contains nine sample applications designed
to illustrate specific GPIB concepts and techniques that can help you write
your own applications. The description of each example includes the
programmer’s task, a program flowchart, and numbered steps that correspond
to the numbered blocks on the flowchart.
• Chapter 3, Developing Your Application, explains how to develop a GPIB
application program using NI-488 functions and NI-488.2 routines.
• Chapter 4, Debugging Your Application, describes several ways to debug
your application program.
• Chapter 5, ibic—Interface Bus Interactive Control Utility, introduces you to
ibic, the interactive control program that you can use to communicate
with GPIB devices through functions you enter at your keyboard.
• Chapter 6, GPIB Programming Techniques, discusses the following GPIB
topics: data transfer termination methods, waiting for GPIB conditions,
device-level calls and bus management, serial polling and SRQ servicing,
and parallel polling.
• Chapter 7, ibconf—Interface Bus Configuration Utility, contains a
description of ibconf, the software configuration program you can use to
configure the NI-488.2M software.

About This Manual
NI-488.2M SRM for OS/2 xii © National Instruments Corp.
• Appendix A, Status Word Conditions, gives a detailed description of the
conditions reported in the status word, ibsta.
• Appendix B, Error Codes and Solutions, lists a description of each error,
some conditions under which it might occur, and possible solutions.
• 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 a description of terms,
including abbreviations, acronyms, metric prefixes, mnemonics, and
symbols, that this manual uses.
• The Index contains an alphabetical list of key terms and topics in this
manual and it includes the page where you can find each term and topic.
Conventions Used in This Manual
The following conventions are used in this manual.
italic Italic text denotes emphasis, cross references, field
names, 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 you
enter from the keyboard. Sections of code,
programming examples, and syntax examples also
appear in this font. This font is also used for the
proper name of disk drives, paths, directories, device
names, variables, and for statements taken from
program code.
bold monospace Bold text in this font denotes the messages and responses
that the computer automatically prints to the screen.

About This Manual
© National Instruments Corp. xiii NI-488.2M SRM for OS/2
italic monospace Italic lowercase text in this font denotes that you must
supply the appropriate words or values in the place of
these items.
<> Angle brackets enclose the name of a key on the
keyboard—for example, <PageDown>.
<Enter> Key names are capitalized.
- A hyphen between two or more key names enclosed
in angle brackets denotes that you should
simultaneously press the named keys—for example,
<Control-C>.
enter Enter is reserved to mean that the commands
immediately succeeding the word must be typed into
the computer and then executed by pressing the
<Return> key on the keyboard.
IEEE 488 and IEEE 488 and IEEE 488.2 refer to the
IEEE 488.2 ANSI/IEEE Standard 488.1-1987 and the
ANSI/IEEE Standard 488.2-1987, respectively,
which define the GPIB.
NI-488.2M software NI-488.2M software refers to the NI-488.2M software
for OS/2 unless otherwise noted.
Abbreviations, acronyms, metric prefixes, mnemonics, symbols, and terms are
listed in the Glossary.

About This Manual
NI-488.2M SRM for OS/2 xiv © National Instruments Corp.
How to Use This Manual Set
NI-488.2M Software
Reference Manual
for OS/2
Application
Development
and Examples
Getting Started
Manual
Novice
Users
Installation and
Configuration
NI-488.2M Function
Reference Manual
for OS/2
Experienced
Users
Function
and Routine
Descriptions
Use the getting-started manual to install and configure your GPIB hardware and
NI-488.2M software for OS/2.
Use the software reference manual if you want to learn the basics of GPIB and
how to develop an application program. The software reference manual also
contains debugging information and detailed examples.
Use the function reference manual for specific information about each NI-488
function and NI-488.2 routine, such as format, parameters, and possible errors.

About This Manual
© National Instruments Corp. xv NI-488.2M SRM for OS/2
Related Documentation
The following documents contain information that you may find helpful as you
read this manual:
•OS/2 Technical Library, Application Design Guide
•OS/2 Technical Library, Control Program Programming Reference
• OS/2 Technical Library, Programming Guide Volume I
•OS/2 Technical Library, Programming Guide Volume II
•OS/2 Technical Library, Programming Guide Volume III
• ANSI/IEEE Standard 488.1-1987, IEEE Standard Digital Interface for
Programmable Instrumentation.
• ANSI/IEEE Standard 488.2-1987, IEEE Standard Codes, Formats, Protocols,
and Common Commands.
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 Corp. 1-1 NI-488.2M SRM for OS/2
Chapter 1
NI-488.2M Software Description
This chapter describes the NI-488.2M software package and explains how the
software works with your OS/2 system.
The NI-488.2M Software Package
The following section highlights important elements of the NI-488.2M software
for OS/2 and describes the function of each element.
NI-488.2M Driver and Driver Utilities
The distribution disk contains the following driver and utility files.
•readme.doc is a documentation file that contains important information
about the NI-488.2M software and a description of any new features.
Before you use the software, read this file for the most recent information.
•install.cmd is an OS/2 command file that performs the software
installation. It does not modify your config.sys file.
•gpib.sys is the software driver file that is loaded at system startup by
OS/2.
•gpib.ddp is a device driver profile. This file is used by the OS/2
command, ddinstal, to control the installation process.
•ibic.exe is an interactive control program that you use to communicate
with the GPIB devices interactively using NI-488.2 functions and routines.
It helps you to learn the NI-488.2 routines and to program your instrument
or other GPIB devices.
•ibconf.exe is a software configuration program that changes the
configuration parameters of the NI-488.2M software.
•ibtest.exe is the software installation test.

NI-488.2M Software Description Chapter 1
NI-488.2M SRM for OS/2 1-2 © National Instruments Corp.
Language Files
The distribution disk contains the following language-related files in the
C subdirectory.
•readme.doc is a documentation file that contains information about the
language interfaces.
•ni488.dll is a 32-bit IBM C language interface Dynamic Link Library (DLL)
file.
•nibor.dll is a 32-bit Borland C language interface DLL file.
•ni488_16.dll is a 16-bit Microsoft C language interface DLL file.
•ni488.lib is an import library for the 32-bit IBM C language interface that you
must link with your IBM C applications.
•nibor.lib is an import library for the 32-bit Borland C language interface that
you must link with your Borland C applications.
•ni488_16.lib is an import library for the 16-bit Microsoft C language
interface that you must link with your Microsoft C applications.
•decl.h is a 32-bit include file. It contains NI-488 functions and NI-488.2
routine prototypes and various predefined constants.
•decl_16.h is a 16-bit include file. It contains NI-488 functions and
NI-488.2 routine prototypes and various predefined constants.
Example Program Files
The distribution disk contains the following example program files.
•simple.c is a C program that illustrates basic communication between a
computer and a GPIB device.
•clr_trg.c is a C program that illustrates how to clear or trigger GPIB devices.
•asynch.c is a C program that illustrates how to perform asynchronous I/O.

Chapter 1 NI-488.2M Software Description
© National Instruments Corp. 1-3 NI-488.2M SRM for OS/2
•rqs.c is a C program that illustrates device requests using NI-488 functions.
•easy4882.c is a C program that illustrates basic communication with
IEEE 488.2 compliant devices using NI-488.2 routines.
•eos.c is a C program that shows the use of the end-of-string character.
•rqs4882.c is a C program that illustrates serial polls using NI-488.2 routines.
•ppoll.c is a C program that illustrates parallel polls using NI-488.2 routines.
•non_cic.c is a C program that illustrates communication when the GPIB board
is not the Controller.
API-Related Files
The distribution disk contains the following API-related files in the API
subdirectory.
•readme.api is a documentation file that contains information about the
OS/2 API functions.
•nicode.h is a C language declaration file that contains definitions of NI-
488.2M function codes and other NI-488.2M-related constant and structure
definitions.
•nictl_32.h is a C language declaration file that contains a macro
definition. You can use this definition in place of the DosDevIOCtl
definition for applications that use 32-bit compilers.
•nictl_16.h is a C language declaration file that contains a macro
definition. You can use this definition in place of the DosDevIOCtl
definition for applications that use 16-bit compilers.
•dsamp_32.c is a 32-bit C sample program using API device-level calls.
•dsamp_16.c is a 16-bit C sample program using API device-level calls.
•bsamp_32.c is a 32-bit C sample program using API board-level calls.
•bsamp_16.c is a 16-bit C sample program using API board-level calls.

NI-488.2M Software Description Chapter 1
NI-488.2M SRM for OS/2 1-4 © National Instruments Corp.
How the NI-488.2M Software Works with OS/2
The NI-488.2M driver operates as a standard OS/2 system device driver, which
is loaded at system startup. OS/2 device driver services are available to all OS/2
programs running in the system.
Figure 1-1 shows two ways you can access the NI-488.2M driver. You can use
either the NI-488.2 language interface or the OS/2 API (Application Program
Interface) calls. Both methods access the NI-488.2M driver through the OS/2
system. The driver then accesses your GPIB hardware.
OS/2 System
NI-488.2M Driver
GPIB Hardware Interface
OR User
Application
Program
IBIC
utility for using
NI-488.2 commands
interactively
NI-488.2 Language Interface
OR User
Application
Program
OS/2 Application
Program
Interface
Figure 1-1. How the NI-488.2M Software Works with OS/2

Chapter 1 NI-488.2M Software Description
© National Instruments Corp. 1-5 NI-488.2M SRM for OS/2
The remainder of this chapter discusses the basics of GPIB and how to set up
your system. For application program examples, refer to Chapter 2, Application
Examples. For information about writing an application program, refer to
Chapter 3, Developing Your Application.
GPIB Overview
The following sections describe the elements of a GPIB system.
The IEEE 488 Standard and GPIB
The ANSI/IEEE Standard 488.1-1987, IEEE Standard Digital Interface for
Programmable Instrumentation, describes a standard interface for
communication between instruments and controllers from various vendors. It
contains information about electrical, mechanical, and functional specifications.
The ANSI/IEEE Standard 488.2-1987, Codes, Formats, Protocols, and
Common Commands, defines a bus communication protocol, a common set of
data codes and formats, and a generic set of common device commands.
The GPIB (General Purpose Interface Bus) is a digital, 8-bit parallel
communications interface with data transfer rates of 1 Mbytes/s and above. The
bus supports one System Controller, usually a computer, and up to 14 additional
instruments.
Talkers, Listeners, and Controllers
Devices on the GPIB can be Talkers, Listeners, or Controllers. A Talker sends
out data messages. Listeners receive data messages. The Controller, usually a
computer, manages the flow of information on the bus. It defines the
communication links and sends GPIB commands to devices.
Some devices are capable of playing more than one role. A digital voltmeter,
for example, can be a Talker and a Listener. If your personal computer has a
GPIB interface board and GPIB software installed, it can function as a Talker,
Listener, and Controller.