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
(512) 250-9119
©
Copyright 1985 by National Instruments
All Rights Reserved
LIMITED WARRANTY
The GPIB-MAC is warranted against defects in materials and workmanship 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 commitment 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 communications. 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 004000-000345-4.
©
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 measurement 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 Programmable 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
800/531-5066 (outside Texas)
800/IEEE-488
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
l-GPIB
(inside Texas)
November 1985
Organization of the Manual
©
National Instruments
Section
One -
Section Two
Section Three
Section Four
Appendix A
Appendix B
Appendix C
Appendix D
Appendix F
Appendix F
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.
Appendix G
Appendix H
Appendix1
. . .
Vlll
PREFACE
-
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.
November 1985
©
National Instruments
TABLE OF
1 SECTION ONE
1
1
1 Description of the Model GPIB-MAC
2
2 Physical Specifications
3
3
4
6
6
7
::
7
!
9
10
11
12
14
15
Introduction to the GPIB-MAC
Introduction to the IEEE-488 (GPIB)
Environmental Specifications
Quick Reference Chart
The Model GPIB-MAC Front Panel
The Model GPIB-MAC Back Panel
Mechanical Specifications
Electrical Specifications
SECTION TWO
Inspection
Installation
Voltage Requirements
Configure the GPIB-MAC Rear Panel Switches
Switches 1 and 2 - Factory Use Only
Switch 3 - Word Length
Switch 4 - Stop Bits
Switches 5 and 6 - Parity Type
Switches
Connect Cables
Turn Power Switch to On
-
Introduction
-
Installation and Configuration
7,8,
and 9 - Baud Rate
CONTENTS
17 SECTION THREE
17
17
18
18
19
19
19
;:
;:
22
ix
Programming Messages
ProgrammingMessage Format
How Messages are Processed
Function Names
Function Argument Delimiters
Abbreviations for Arguments
GPIB Address
Numeric String Argument
Status Information
Serial Port Error Handling
GPIB Read and Write Termination Method
Default Settings
TABLE OF
CONTENTS
-
Programming the GPIB-MAC
November 1985
List of Functions by Group
;:
GPIB Functions
Serial Port Functions
;z
25
General Use Functions
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
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* frequently used function
TABLE OF CONTENTS
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93 APPENDIX A - Multiline Interface Messages
National Instruments
97 APPENDIX B
97
100
103
105 APPENDIX C
107 APPENDIX D - Operation of the GPIB
107
107
108
109
110
110
111
111
114
115 APPENDIX E - Common Questions
117 APPENDIX F - Parallel Polling
:::
119
119
119
Status Bits
GPIB Error Codes
Serial Port Error Codes
Types of Messages
Talkers, Listeners, and Controllers
System Controller and Active Controller
GPIB Signals
Data Lines
Handshake Lines
Interface Management Lines
Physical and Electrical Characteristics
Configuration Restrictions
Configuration
Operation
The
Parallel Poll
Disabling Parallel Poll Response
Example
-
Status Information
-
Changing from 115 VAC to 230 VAC
121 APPENDIX G - Setting Switches
123 APPENDIX H - Sample Program
123
123
123
xi
General Steps
Using an HP 7475A Plotter with a Macintosh
Getting Ready to Program
TABLE
OF
CONTENTS
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124
124
125
125
125
127
Programming Steps
Step
1
-
stat Function
Step 2 - Serial Port Functions
Step 3 - GPIB Initialization Functions
Step 4 - Communicate with rd and wrt
APPENDIX I - Serial Port Sample Program
Functions
xii
TABLE
OF CONTENTS
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LIST OF FIGURES
SECTION ONE
-
Introduction
2 Model GPIB-MAC
3
Front Panel of the GPIB-MAC
5
Back Panel of the Model GPIB-MAC
SECTION TWO
8
GPIB-MAC DIP Switch
8
Factory Use Only
9
7-bit Word Length
9
8-bit Word Length
10 1 Stop Bit
10 2 Stop Bits
11
Configuration for Parity Types
12 Baud Rate Settings
14
GPIB-MAC with Serial Cable, Power Cable, and GPIB Cable
-
Installation and Configuration
APPENDIX C - Changing from 115 Volts AC to 230
Volts AC
105 GPIB-MAC with Cover Removed
APPENDIX D - Operation of the GPIB
109 GPIB Cable Connector
112 Linear Configuration of GPIB Devices
113 Star Configuration of GPIB Devices
xiii
TABLE OF CONTENTS
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LIST OF TABLES
SECTION ONE
Front Panel LEDs
4
SECTION THREE
22 Serial Port Characteristics
22 GPIB Characteristics
23 I/O Functions
23 Bus Management Functions
23 GPIB Initialization Functions
24 Serial Poll Functions
24 Low-level Controller Functions
24 Parallel Poll Functions
Serial Port Initialization Functions
25
25 General Use Functions
25 GPIB-MAC Functions
-
Introduction
-
Programming the GPIB-MAC
SECTION FOUR - Functions
Data Transfer Termination Methods
39
76 GPIB Status Conditions
77 GPIB Error Conditions
Serial Port Error Conditions
78
86 Wait Mask Values
xiv
TABLE
OF CONTENTS
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November 1985
-
Section One
This section provides brief introductions to the GPIB-MAC and the
IEEE-488. It also describes the physical, electrical, and
environmental characteristics of the GPIB-MAC.
Introduction
National Instruments
Introduction to the GPIB-MAC
The GPIB-MAC is a high performance GPIB-to-Macintosh
interface. The GPIB-MAC together with a Macintosh personal
computer provide a means of Controlling, Talking, and Listening on
the GPIB.
The GPIB-MAC has all the software and logic required to
implement the physical and electrical specifications of the IEEE-488.
It is capable of interpreting and executing high level commands that
you send to it over the Macintosh serial port.
Introduction to the IEEE-488 (GPIB)
The IEEE-488, also known as the General Purpose Interface Bus or
GPIB, is a high speed parallel bus structure originally designed by
Hewlett-Packard. It is generally used to connect and control
programmable instruments, but has gained popularity in other
applications, such as intercomputer communication and peripheral
control.
The specifications of the GPIB are too lengthy and comprehensive
to be explained in this manual. However, Appendix D, ‘Operation
of the GPIB,” contains a summary of pertinent IEEE-488
information you might find useful.
Description of the Model GPIB-MAC
Included here are the GPIB-MAC environmental, physical, and
electrical specifications.
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SECTION ONE - INTRODUCTION
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National Instruments
Environmental Specifications
The GPIB-MAC is designed to operate in temperatures ranging from
10 to 40 degrees Celsius, and in humidity ranging from 10% to 95%
non-condensing.
The GPIB-MAC can be stored in temperatures ranging from 0 to 70
degrees Celsius.
Physical Specifications
The GPIB-MAC, shown in the following figure, is housed in a
structural foam injection molded case. The unit can be rack mounted
or placed on a table.
Model GPIB-MAC
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SECTION ONE - INTRODUCTION
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National Instruments
Ouick Reference Chart.
On the back panel of the GPIB-MAC is a reference chart that
contains the information you need to configure the rear panel
switches of the GPIB-MAC. More detailed configuration
information is included in Section Two.
The Model GPIB-MAC Front Panel
The front panel of the GPIB-MAC is shown in the following figure.
The six light emitting diodes (LEDs) show the current status of the
GPIB-MAC.
3
SECTION
NATIONAL
INSTRUMENTS
IEEE-488 (MAC
[‘-p*ll’;“~][^;“l
Front Panel of the GPIB-MAC
ONE -
INTRODUCTION
GPIB-MAC
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November 1985
The following table shows what each LED indicates when lit.
National Instruments
LED
POWER
READY
TALK
LISTEN
ATN
SRQ
PurDose
indicates power is on.
indicates that the power-on self-test has passed
successfully and unit is ready to operate.
indicates that the GPIB-MAC is currently
addressed to Talk on the GPIB.
indicates that the GPIB-MAC is currently
addressed to Listen on the GPIB.
indicates that the GPIB signal line ATN* is
asserted (low).
indicates that the GPIB signal line SRQ* is
asserted (low).
The Model GPIB-MAC Back Panel.
The
back panel of the GPIB-MAC is shown in the following figure.
The power connector, 9-position configuration switch, g-pin D-
subminiature connector, and GPIB (IEEE-488) port are shown.
4
SEaION
ONE - INTRODUCTION
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National Instruments
g-pin
D-subminiature
Connector
Back Panel of the Model GPIB-MAC
5
SECTION ONE - INTRODUCTION
Power
Connector
9-position
Configuration
Switch
GPIB
(IEEE-488)
Port
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National Instruments
Mechanical
Width:
Height:
Depth:
Weight:
&ecificationS
216.9 mm (8.5 inches)
88.4 mm (3.5 inches)
330.2 mm (13.0 inches)
5.25 pounds
Electrical Specifications
The GPIB-MAC is designed to operate under the following electrical
specifications.
Power:
115
volts AC or 230 volts AC; 50/60 Hz;
20 VA
Typical Current:
Fuse Type:
.09
amps AC
115
230
volts AC use
l/4
amp Fast
volts AC use l/8 amp Fast
6
SECTION ONE - INTRODUCTION
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November 1985
Section Two
-
Installation and
National Instruments
Configuration
Use this section to install and configure the GPIB-MAC. Then,
read Sections Three and Four to learn about how to program the
GPIB-MAC.
Inspection
Before you install the GPIB-MAC, 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
packaging material for possible inspection or for reshipment.
If the equipment appears to be damaged, do not attempt to operate
it. Contact National Instruments for instructions.
Installation
There are four basic steps to installing the GPIB-MAC.
1. Verify voltage requirements
2. Configure GPIB-MAC rear panel switches
3. Connect cables
4. Turn power switch to On
Voltage Requirements
The
GPIB-MAC is shipped with the internal voltage selector switch
configured to operate on a standard 115 VAC power line.
If your setup requires 230 VAC, refer to Appendix C to learn how
to open the box to change the voltage selector switch.
7
SECTION TWO: INSTALLATION AND CONFIGURATION
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National Instruments
Configure the GPIB-MAC Rear Panel Switches
Configure the GPIB-MAC by setting the switches of the g-pin, rear
panel DIP switch. The following figure shows the switches
labeled for factory use only, 7- or
g-bit
word length, one or two
stop bits, odd/even or no parity, and baud rate.
D=OFF
l=ON
011
4800
100
9600
101
19.2K
110
38.4K
111
57.6K
GPIB-MAC DIP Switch
Switches 1 and 2 - Factorv Use
Only
Switch 1 and 2 are for factory use only and should always be
positioned in the off position as shown below.
Factory Use Only
8
SECTION TWO: INSTALLATION AND CONFIGURATION
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National Instruments
Switch 3
Configure the
setting switch 3. The off position indicates 7 bits, the on position
indicates 8.
-
Word
Length
GPIB-MAC
for a serial word length of 7 or 8 bits by
7-bit
Word Length
g-bit
Word Length
9
SECTION TWO: INSTALLATION AND CONFIGURATION
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National InstrumentsNovember 1985
Switch 4
- StoD
Bits
Configure the GPIB-MAC for a stop bit length of 1 or 2 bits by
setting switch 4. The off position indicates 1 bit, the on position
indic&s
2.
1 Stop Bit
2 Stop Bits
10
SECTION TWO: INSTALLATION AND CONFIGURATION
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National Instruments
Switches 5 and 6 - Paritv
TVD~
The GPIB-MAC can transmit and receive serial data using odd
parity, even parity, or no parity. Configure the GPIB-MAC for
the correct parity according to the following figure. Note that
switch 5 indicates parity off. Switch 6 indicates parity odd or
even. If switch 5 is set to off, switch 6 is ignored.
Switch Settines
_
1 2 3 415
6i7
8 9
Parity
Odd
Even
Type
Parity
Parity
11
SECTION
Pa&y Inhibit
Parity
b_______.
Two:
INSTALLATION AND CONFIGURATION
Inhibit
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November 1985
.
witches 7. 8. and 9 - Baud Rate
Configure the GPIB-MAC for the appropriate baud rate by setting
switches
7,8,
and 9 according to the following figures.
National Instruments
Switch Settings
~1
1200
Baud Rate
300
2400
4800
12
SECTION TWO: INSTALLATION AND CONFIGURATION
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National Instruments
Baud
9600
19.2K
38.4K
57.6K
If you need more information on how the switches of the GPIB-
MAC
should be set, refer to Appendix G.
13
SECTION TWO: INSTALLATION AND CONFIGURATION
November 1985
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National Instruments
Connect Cables
You must connect three cables to operate the GPIB-MAC: the serial
cable, the power cable, and the GPIB cable. The three cables all
connect to the GPIB-MAC via the rear panel, as shown in the
following figure.
GPIB-MAC with Serial Cable, Power Cable, and GPIB
Cable
The power cord receptacle is located at the top left of the rear panel.
If 115 VAC is required, use the standard power cable supplied with
the unit. If 230 VAC is required, use a cable that is compatible with
both the GPIB-MAC power receptacle and the 230 VAC plug
configuration.
The GPIB cable should be connected to the 24-pin GPIB connector
on the lower right of the rear panel. The connectors can be piggybacked to add more GPIB devices to the bus. Connect the serial
cable to the
GPIB-MAC. Connect the other end of the cable to your Macintosh
modem port.
14
SECTION TWO: INSTALLATION AND CONFIGURATION
9-p&
D-subminiature connector on the back of the
November 1985
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National Instruments
Turn Power Switch to On
The power switch is located at the left of the power cord receptacle.
Turn the switch to On. There will be a slight delay while the unit
performs a self-test of all the internal circuitry. The test does not
affect devices connected to the GPIB-MAC. When the test
successfully completes, the BEADY LED comes on. If it does not,
verify your switch settings and the power connections. If the
BEADY LED still fails to come on, contact National Instruments.
Note - The rear panel switches are read by the fiiware only when
the unit is powered on. After changing switch settings, turn the
power switch off and back on for the change to take effect. Also,
the GPIB address of the GPIB-MAC at power on is 0 with
secondary addressing disabled. You can change these values after
power-on using a programming message.
15
SECTION TWO: INSTALLATION AND CONFIGURATION
November 1985
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National Instruments
Section Three - Programming the GPIB-MAC
This section shows how to program the GPIB-MAC by using
programming messages and data strings. It describes programming
messages, their format, and how they areprocessed, along with the
functions and function arguments that make up the programming
messages.
Programming Messages
You program the GPIB-MAC by sending it programming messages
(which are ASCII strings) and data strings by way of its serial port.
Programming Message Format
A
arguments (optional), followed by a carriage return (<CR>), a
linefeed (<LF>),
(<CR><LF>).
You may enter programming messages in any combination of
uppercase and lowercase letters.
Example of 3 Proaramming Message
The following line of BASIC code:
contains the function name
programming message tells the GPIB-MAC to clear the devices at
GPIB addresses 3 and 4. PRINT #l is the BASIC command to
send characters to the serial port after the serial port has been opened
with the “OPEN COM...” statement. In this example, BASIC
automatically sends a
17
amming message consists of a function name, one or more
progr
or a carriage return followed by a
PRINT
<CR>,
SECTION THREE - PROGRAMMING THE GPIB-MAC
#l,“clr 34”
clr
and the arguments 3 and 4. This
so it is not necessary to include it here.
linefeed
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National Instruments
The cmd
string which may contain 7- or
Example ef 1~
The following lines of BASIC code:
contain the function name
“IN;CI;“.
write to the device at primary address 2.
“IN;CI;” is the data string which contains the data
on the GPIB. In this case, a
following each print string, so, again, it is not necessary to include it
here.
and
wrt
programming messages are followed by a data
ProFamming
PRINT # 1,
PRINT
This programmin
g-bit
data
Message with Data String
“wrt 2”
#l, ‘TN;CI;”
wrt, the
g
<CR>
argument 2, and the data string
message is telling the GPIB-MAC to
wrt
will send out
is automatically sent by BASIC
How Messages are Processed
g
The GPIB-MAC processes a programmin
line basis. The GPIB-MAC buffers the entire message, interprets
the function name and arguments, then executes the message.
message on a line-by-
The data portions of the
on a line-by-line basis. The data immediately following a
cmd are
sent directly to the GPIB.
wrt
and
cmd
functions are not processed
wrt
and a
Function Names
The function names have been selected to indicate each function’s
purpose, thereby making your programs easy to understand.
However, if you wish to reduce some overhead in your program
and do not mind giving up these advantages, you may use only as
much of the function name as is necessary to distinguish it from
other functions. This abbreviated form of the function name is
shown in
of the function descriptions.
18
boldface in the
SECTION THREE - PROGRAMMING THE GPIB-MAC
function tables and in the syntax portions
November 1985
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National Instruments
For example, the
wait
function may be called using either of the
next two statements:
PRINT
PRINT
#l,
#l,
“wait
“wa
\x5000”
\x5000”
Function Argument Delimiters
When you type in a function, separate the
function name with at least one space. Separate each additional
argument with at least one space or a comma.
In the syntax portions of the function descriptions in Section Four
the square brackets
(n)
are optional. If you want to include optional
information, you do not need to type the brackets, only the
information inside the brackets.
Abbreviations for Arguments
The function descriptions in Section Four use abbreviations for
some arguments. They are as follows:
addr a GPIB address
alist one or more addrs
boo1
a boolean value: 1 = true, on, or enable
0 = false, off, or disable
fmt
argument from the
GPIB Address
Each device on the GPIB has a GPIB address. The GPIB-MAC’s
address is 0 at power on and may be changed using the
caddr
function. Refer to the manuals of your GPIB devices to learn their
addresses. You will need to know these when you begin to
program the GPIB-MAC.
Only the lower five bits of each GPIB address are significant. These
bits may be in the range from 0 through 30 for both the primary and
the secondary address. For example, the binary value 01100010
(decimal 98) is interpreted as decimal 2.
19
SECTION
THREFi -
PROGRAMMING THE GPIB-MAC
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