National Instruments GPIB-MAC User manual

National Instruments
Model GPIB-MAC User Manual
Part Number 320064-01
November 1985 Edition
National Instruments
12109 Technology Boulevard
Austin, Texas 78727
[phone]
© Copyright 1985 by National Instruments
All Rights Reserved

LIMITED WARRANTY
The GPIB-MAC is warranted against defects in materials and work-
manship for a period of one year from date of shipment.National
Instruments will repair or replace equipment which proves to be
defective during the warranty period. This warranty includes parts
and labor. A Returned Material Authorization (RMA) number must
be obtained from the factory before any equipment is returned for
warranty. During the warranty period, the owner may return failed
parts to National Instruments for repair. National Instruments will
pay the shipping costs of returning the part to the owner.All items
returned to National Instruments for repair must be clearly marked
on the outside of the package with a RMA.No other warranty is
expressed or implied National Instruments shall not be liable for
consequential damages. Contact National Instruments for more
information.
IMPORTANT NOTE
The material in this manual is subject to change without notice.
National Instruments assumes no responsibility for errors which
may appear in this manual. National Instruments makes no commit-
ment to update, nor to keep current, the information contained in this
document.
Trademarks
GPIB-MAC is a trademark of National Instruments.
Apple and Macintosh are trademarks of Apple Computer, Inc.
Microsoft is a registered trademark of Microsoft Corporation.

FCC RADIO FREQUENCY INTERFERENCE
COMPLIANCE
This equipment generates, uses, and can radiate radio frequency
energy and if not installed and used in accordance with the
instruction manual, may cause interference to radio communica-
tions. It has been tested using a shielded serial I/O cable and
standard GPIB cable and found to comply within the limits for a
Class A computing device pursuant to Subpart J of Part 15 of FCC
Rules, which are designed to provide reasonable protection against
such interference when operated in a commercial environment
Operation of this equipment in a residential area is likely to cause
interference, in which case the user at his own expense will be
required to take whatever measures may be necessary will be
required to take whatever measures may be necessary to correct the
interference.
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.
Reposition the equipment or receiver.
Reposition the receiver’s antenna.
Unplug any unused I/O cables. Unterminated I/O cables are a
potential source of interference.
Remove any unused circuit boards. Unterminated circuit boards
are also a potential source of interference.

* Be sure the computing device is plugged into a grounded outlet
and that the grounding has not been defeated with a cheater plug.
* Replace the GPIB cable with Hewlett-Packard Model 10833
cable.
If none of these measures resolves your interference problems,
contact the manufacturer or write to the U.S. Government Printing
Office, Washington, D.C. 20402, for the booklet, “How to Identify
and Resolve Radio-TV Interference Problems, “Stock Number 004-
000-000345-4.

November 1985
© National Instruments
Preface
Welcome to the family of National Instruments GPIB products and
to the Model GPIB-MAC.
The Model GPIB-MAC allows the GPIB to be controlled from a
Macintosh personal computer.
About the Manual
The manual is designed for users who have some familiarity with
the Macintosh personal computer, the GPIB, and test and meas-
urement equipment.
For users with less experience, we have included appendixes that
describe the operation of the GPIB.
For more specific details on the operation of the GPIB, refer to the
IEEE Std. 488-1978, “IEEE Standard Digital Interface for Program-
mable Instrumentation.”
Whatever your level of experience, if you encounter problems,
National Instruments has a staff of applications engineers ready to
help you with your particular problem. Just call
800/53 l-GPIB
800/531-5066 (outside Texas)
800/IEEE-488 (inside Texas)
between the hours of 8:00 a.m and 5:00 p.m, Central Time.
Now, look over the next few pages at how the manual is organized
and then at the Table of Contents so that you will be familiar with
the complete contents for future reference.
vii PREFACE

November 1985
Organization of the Manual
Section One -
Section Two -
Section Three -
Section Four -
Appendix A -
Appendix B -
Appendix C -
Appendix D -
Appendix F -
Appendix F -
Appendix G -
Appendix H -
Appendix1 -
© National Instruments
gives brief introductions to the GPIB-MAC and the
IEEE-488.
contains the installation and configuration steps.
explains how to program the GPIB-MAC.
gives a detailed description of each function. The
function descriptions are arranged in alphabetical
order and each contains the syntax and purpose of
the functions, and examples.
contains a table of multiline interface messages.
lists status information.
shows how to change the operating voltage from
115 to 230.
describes the operation of the GPIB.
gives answers to common questions.
explains the use and operation of Parallel Polls.
gives additional detail on setting switches on the
GPIB-MAC.
contains a sample program of general programming
steps.
contains a sample program to control the serial port
of the Macintosh from a C program.
. . .
Vlll
PREFACE

November 1985
© National Instruments
TABLE OF CONTENTS
1 SECTION ONE - Introduction
1
Introduction to the GPIB-MAC
1
Introduction to the IEEE-488 (GPIB)
2
1 Description of the Model GPIB-MAC
Environmental Specifications
3
2 Physical Specifications
Quick Reference Chart
3
The Model GPIB-MAC Front Panel
4 The Model GPIB-MAC Back Panel
6
Mechanical Specifications
6
Electrical Specifications
7 SECTION TWO - Installation and Configuration
::
Inspection
Installation
7
Voltage Requirements
!
Configure the GPIB-MAC Rear Panel Switches
Switches 1 and 2 - Factory Use Only
9
Switch 3 - Word Length
10
Switch 4 - Stop Bits
11 Switches 5 and 6 - Parity Type
12
Switches 7,8, and 9 - Baud Rate
14 Connect Cables
15
Turn Power Switch to On
17 SECTION THREE - Programming the GPIB-MAC
17
Programming Messages
17
Programmin g Message Format
18
How Messages are Processed
18 Function Names
19 Function Argument Delimiters
19
Abbreviations for Arguments
19 GPIB Address
;:
Numeric String Argument
Status Information
;:
Serial Port Error Handling
GPIB Read and Write Termination Method
22
Default Settings
ix
TABLE OF CONTENTS

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0 National Instruments
;:
List of Functions by Group
GPIB Functions
;z
Serial Port Functions
General Use Functions
25
List of Functions in Alphabetical Order
27 SECTION FOUR- Functions
Points to Remember
cat - Become Active Controller
caddr - Change the GPIB Address of the GPIB-MAC
clr - Clear Specified Device *
cmd - Send GPIB Commands
echo - Echo Characters Received from Serial Port
eos - Change/Disable GPIB EOS Termination Mode
eot - Enable/Disable END Message on GPIB Writes
gts - Go from Active Controller to Standby
id.MAC - Identify System
ist - Set or Clear Individual Status Bit
lot-GotoLocal*
on1 - Place the GPlB-MAC Online/Offline
pet - Pass Control
ppc - Parallel Poll Configure
ppu - Parallel Poll Unconfigure
rd - Read Data *
rpp - Request (Conduct) a Parallel Poll
rsc - Request or Release System Control
rsp - Request (Conduct) a Serial Poll
rsv - Request Service/Set or Change Serial Poll Status Byte
sic - Send Interface Clear
spign - Ignore Serial Port Errors
sre - Set or Clear Remote Enable
stat - Return GPIB-MAC Status
tmo - Change or Disable Time Limit
trg - Trigger Selected Device(s) *
wait - Wait for Selected Event
wrt-WriteData*
xon
- Change Serial Port XON/XOFF Protocol
* frequently used function
x
TABLE OF CONTENTS

November 1985
0 National Instruments
93 APPENDIX A - Multiline Interface Messages
97 APPENDIX B - Status Information
97
Status Bits
100 GPIB Error Codes
103
Serial Port Error Codes
105 APPENDIX C - Changing from 115 VAC to 230 VAC
107 APPENDIX D - Operation of the GPIB
107
Types of Messages
107
Talkers, Listeners, and Controllers
108
System Controller and Active Controller
109
GPIB Signals
110
Data Lines
110
Handshake Lines
111
Interface Management Lines
111
Physical and Electrical Characteristics
114
Configuration Restrictions
115 APPENDIX E - Common Questions
117 APPENDIX F - Parallel Polling
::: Operation
Configuration
119
The Parallel Poll
119
Disabling Parallel Poll Response
119
Example
121 APPENDIX G - Setting Switches
123 APPENDIX H - Sample Program
123
General Steps
123
Using an HP 7475A Plotter with a Macintosh
123
Getting Ready to Program
xi TABLE OF CONTENTS

November 1985
0 National Instruments
124 Programming Steps
124
Step 1 - stat Function
125
Step 2 - Serial Port Functions
125
Step 3 - GPIB Initialization Functions
125
Step 4 - Communicate with rd and wrt Functions
127 APPENDIX I - Serial Port Sample Program
xii TABLE OF CONTENTS