National Instruments GPIB-232CV User Manual

© Copyright 1987, 1994 National Instruments Corporation.

All Rights Reserved.

GPIB-232CV

User Manual

IEEE 488 RS-232 Converter

April 1994 Edition

Part Number 320109-01

National Instruments Corporate Headquarters

6504 Bridge Point Parkway
Austin, TX 78730-5039
[phone]
Technical support fax: [phone]

Branch Offices:

Australia 03 879 9422, Austria 0662 435986, Belgium 02 757 00 20,
Canada (Ontario) 519 622 9310, Canada (Québec) 514 694 8521,
Denmark 45 76 26 00, Finland 90 527 2321, France 1 48 65 33 70,
Germany 089 714 50 93, Italy 02 48301892, Japan 03 3788 1921,
Netherlands 01720 45761, Norway 03 846866, Spain 91 640 0085,
Sweden 08 730 49 70, Switzerland 056 27 00 20, U.K. 0635 523545

Limited Warranty

The GPIB-232CV is warranted against defects in materials and
workmanship for a period of two years 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.

A Return Material Authorization (RMA) number must be obtained from the
factory and clearly marked on the outside of the package before any
equipment will be accepted for warranty work. National Instruments will
pay the shipping costs of returning to the owner parts which are covered by
warranty.

National Instruments believes that the information in this manual is
accurate. The document has been carefully reviewed for technical
accuracy. In the event that technical or typographical errors exist, National
Instruments reserves the right to make changes to subsequent editions of
this document without prior notice to holders of this edition. The reader
should consult National Instruments if errors are suspected. In no event
shall National Instruments be liable for any damages arising out of or
related to this document or the information contained in it.

EXCEPT AS SPECIFIED HEREIN, NATIONAL INSTRUMENTS MAKES NO

WARRANTIES

, EXPRESS OR IMPLIED, AND SPECIFICALLY DISCLAIMS

ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A
PARTICULAR PURPOSE

. CUSTOMER’S RIGHT TO RECOVER DAMAGES

CAUSED BY FAULT OR NEGLIGENCE ON THE PART OF

NATIONAL

INSTRUMENTS SHALL BE LIMITED TO THE AMOUNT THERETOFORE

PAID BY THE CUSTOMER

. NATIONAL INSTRUMENTS WILL NOT BE

LIABLE FOR DAMAGES RESULTING FROM LOSS OF DATA

, PROFITS,

USE OF PRODUCTS, OR INCIDENTAL OR CONSEQUENTIAL DAMAGES,
EVEN IF ADVISED OF THE POSSIBILITY THEREOF. This limitation of the

liability of National Instruments will apply regardless of the form of action,
whether in contract or tort, including negligence. Any action against
National Instruments must be brought within one year after the cause of
action accrues. National Instruments shall not be liable for any delay in
performance due to causes beyond its reasonable control. The warranty
provided herein does not cover damages, defects, malfunctions, or service
failures caused by owner’s failure to follow the National Instruments
installation, operation, or maintenance instructions; owner’s modification of
the product; owner’s abuse, misuse, or negligent acts; and power failure or

surges, fire, flood, accident, actions of third parties, or other events outside
reasonable control.

Copyright

Under the copyright laws, this publication may not be reproduced or
transmitted in any form, electronic or mechanical, including photocopying,
recording, storing in an information retrieval system, or translating, in
whole or in part, without the prior written consent of National Instruments
Corporation.

Trademarks

Product and company names listed are trademarks or trade names of their
respective companies.

Warning Regarding Medical and Clinical Use

of National Instruments Products

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

FCC/DOC Radio Frequency

Interference Compliance

This equipment generates and uses radio frequency energy and, if not
installed and used in strict accordance with the instructions in this manual,
may cause interference to radio and television reception. This equipment
has been tested and found to comply with the following two regulatory
agencies:

Federal Communications Commission

This device complies with Part 15 of the Federal Communications
Commission (FCC) Rules for a Class A digital device. Operation is subject
to the following two conditions:

1. This device may not cause harmful interference in commercial
environments.

2. This device must accept any interference received, including
interference that may cause undesired operation.

Canadian Department of Communications

This device complies with the limits for radio noise emissions from digital
apparatus set out in the Radio Interference Regulations of the Canadian
Department of Communications (DOC).

Le présent appareil numérique n’émet pas de bruits radioélectriques dépassant les
limites applicables aux appareils numériques de classe A prescrites dans le
règlement sur le brouillage radioélectrique édicté par le ministère des
communications du Canada.

Instructions to Users

These regulations are designed to provide reasonable protection against
harmful interference from the equipment to radio reception in commercial
areas. Operation of this equipment in a residential area is likely to cause
harmful interference, in which case the user will be required to correct the
interference at his own expense.

There is no guarantee that interference will not occur in a particular
installation. However, the chances of interference are much less if the
equipment is installed and used according to this instruction manual.

If the equipment does cause interference to radio or television reception,
which can be determined by turning the equipment on and off, one or more
of the following suggestions may reduce or eliminate the problem.

• Operate the equipment and the receiver on different branches of your
AC electrical system.

• Move the equipment away from the receiver with which it is interfering.

• Reorient or relocate the receiver’s antenna.

• Be sure that the equipment is plugged into a grounded outlet and that
the grounding has not been defeated with a cheater plug.

Notice to user: Changes or modifications not expressly approved by

National Instruments could void the user’s authority to
operate the equipment under the FCC Rules.

If necessary, consult National Instruments or an experienced radio/television
technician for additional suggestions. The following booklet prepared by
the FCC may also be helpful: How to Identify and Resolve Radio-TV
Interference Problems. This booklet is available from the U.S. Government
Printing Office, Washington, DC 20402, Stock Number 004-000-00345-4.

© National Instruments Corp. vii GPIB-232CV User Manual

Contents

About This Manual

Organization of This Manual................................................... xi

Conventions Used in This Manual........................................... xii

Related Documentation............................................................ xiii

Customer Communication ....................................................... xiii

Chapter 1
Description of the GPIB-232CV

............................................... 1-1

Introduction.............................................................................. 1-1

What Your Kit Contains .......................................................... 1-2

Optional Equipment................................................................. 1-3

The GPIB-232CV Front Panel................................................. 1-3

The GPIB-232CV Rear Panel .................................................. 1-5

The RS-232 Connector .............................................. 1-6

The GPIB Connector ................................................. 1-7

Chapter 2
Configuration and Installation

................................................ 2-1

Choosing Between D Mode or C Mode................................... 2-1

Installation................................................................................ 2-2

Step 1. Inspection .................................................... 2-3

Step 2. Verify the Voltage Requirement ................. 2-3

Step 3. Configure the Operating Parameters........... 2-3

Set Configuration Switches......................... 2-4

Step 4. Connect the Cables...................................... 2-10

Step 5. Power on the Unit........................................ 2-10

Operation.................................................................................. 2-10

Chapter 3
Operation

........................................................................................... 3-1

D Mode Operation ................................................................... 3-2

Data Transfers and Buffering .................................... 3-2

Choosing a Serial Port Buffer Size............................ 3-2

Using the SRQ Feature .............................................. 3-3

Enabling the SRQ Feature........................... 3-3

Conditions that Assert SRQ ........................ 3-4

Serial Poll Responses ................................................ 3-4

Listen-Only Mode...................................................... 3-4

Contents

GPIB-232CV User Manual viii © National Instruments Corp.

Special Conditions in D Mode .................................. 3-5

C Mode Operation.................................................................... 3-5

Modes of Operation within C Mode.......................... 3-5

Time Termination Mode ............................. 3-6

<CR> or <LF> Termination Mode ............. 3-6

No-Swap Mode ........................................... 3-7

Buffering and Handshaking ..................................................... 3-8

Hardware Handshake................................................. 3-8

XON/XOFF ............................................................... 3-9

Appendix A
Hardware Specifications

.............................................................. A-1

Appendix B
Interfacing to a Serial Device

.................................................... B-1

The RS-232C Standard ............................................................ B-1

The RS-232C Serial Port.......................................................... B-1

Interfacing the GPIB-232CV to a DCE .................................. B-3

Interfacing the GPIB-232CV to a DTE .................................. B-5

Appendix C
Application Examples

................................................................... C-1

Using the GPIB-232CV as a High-Speed Print Spooler.......... C-1

Using the GPIB-232CV to Connect a HP7475 GPIB

Plotter to a PC Serial Port ........................................................ C-4

Appendix D
Customer Communication

.......................................................... D-1

Glossary.............................................................................................. G-1

Contents

© National Instruments Corp. ix GPIB-232CV User Manual

Figures

Figure 1-1. The GPIB-232CV............................................................. 1-1

Figure 1-2. The GPIB-232CV Front Panel.......................................... 1-3

Figure 1-3. The GPIB-232CV Rear Panel........................................... 1-5

Figure 1-4. The RS-232 Connector and Signal Designations.............. 1-6

Figure 1-5. The GPIB Connector and Signal Designations ................ 1-7

Figure 2-1. Example of C Mode System Setup................................... 2-1

Figure 2-2. Example of D Mode System Setup................................... 2-2

Figure 2-3. Factory Default Settings for Switch U22.......................... 2-4

Figure 2-4. Factory Default Settings for Switch U20.......................... 2-8

Figure B-1. DTE-to-DCE Cable Configuration .................................. B-3

Figure B-2. Minimum DTE-to-DCE Cable Configuration .................. B-4

Figure B-3. Null Modem Cable Configuration .................................... B-5

Figure B-4. Minimum Null Modem Cable Configuration................... B-6

Figure C-1. Example of Print Spooler Setup........................................ C-2

Tables

Table 1-1. LED Descriptions.............................................................. 1-4

Table 2-1. Configuration Parameters for U22 Switch 1 .................... 2-5

Table 2-2. Configuration Parameters for U22 Switches 2 and 3........ 2-5

Table 2-3. Configuration Parameters for U22 Switches

4 through 8 ........................................................................ 2-6

Table 2-4. Configuration Parameters for U20 Switches

1 through 5 ........................................................................ 2-9

Table 2-5. Configuration Parameters for U20 Switches

6 through 8 ........................................................................ 2-9

Table A-1. Electrical Characteristics .................................................. A-1

Table A-2. Environmental Characteristics.......................................... A-1

Table A-3. Physical Characteristics .................................................... A-2

Table B-1. RS-232 Serial Port Signals................................................ B-2

© National Instruments Corp. xi GPIB-232CV User Manual

About This Manual

The GPIB-232CV User Manual describes the features, functions, and
operation of the Product. The GPIB-232CV is one of National Instruments
family of MicroGPIB products. These products are high-performance,
low-cost IEEE 488 support items, packaged in small all-metal cases,
capable of being rack mounted.

Organization of This Manual

The GPIB-232CV User Manual is organized as follows:

• Chapter 1, Description of the GPIB-232CV, contains a brief overview of
the GPIB-232CV, lists the contents of your kit and optional equipment,
and describes the panels of the GPIB-232CV.

• Chapter 2, Configuration and Installation, describes the procedures for
configuring and installing the GPIB-232CV.

• Chapter 3, Operation, contains information about operating the
GPIB-232CV in D mode or C mode and information about data buffering
and handshaking.

• Appendix A, Hardware Specifications, lists the electrical, environmental,
and physical specifications of the GPIB-232CV.

• Appendix B, Interfacing to a Serial Device, contains information about
the RS-232 port and how to connect the GPIB-232CV to your serial
device. This information is useful if you want to build your own serial
cable.

• Appendix C, Application Examples, contains an example showing how to
use a GPIB-232CV as a high-speed print spooler and an example
showing how to use a GPIB-232CV to interface a HP7475 plotter to a
computer running AUTOCAD.

• Appendix D, Customer Communication, contains forms you can use
when requesting help from National Instruments or to comment on our
products and manuals.

About This Manual

GPIB-232CV User Manual xii © National Instruments Corp.

• The Glossary contains an alphabetical list and description of terms used
in this manual including abbreviations, acronyms, metric prefixes,
mnemonics, and symbols.

Conventions Used in This Manual

The following conventions are used in this manual:
italic Italic text denotes emphasis, a cross reference, or

an introduction to a key concept.

monospace Text in this font denotes text or characters that

are to be literally input from the keyboard,
sections of code, programming examples, syntax
examples, and names of variables.

bold Bold text in this manual denotes a signal name or

a front panel LED indicator.

<> Angle brackets enclose the ASCII character

symbols for certain keystrokes. For example,
<CR> for carriage return and <LF> for linefeed.

- A hyphen between two or more key names

enclosed in angle brackets denotes that you
should simultaneously press the named keys–for
example, <Control-Alt-Delete>.

IEEE 488 and IEEE 488 and IEEE 488.2 are used throughout
IEEE 488.2 this manual to refer to the ANSI/IEEE Standard

488.1-1987 and the ANSI/IEEE Standard

488.2-1987, respectively, which define the
GPIB.

RS-232 RS-232 is used throughout this manual to refer

to the ANSI/EIA-232-C standard.

Abbreviations, acronyms, metric prefixes, mnemonics, and terms are listed
in the Glossary.

About This Manual

© National Instruments Corp. xiii GPIB-232CV User Manual

Related Documentation

The following documents contain information that you may find helpful as
you read this manual:

• ANSI/EIA-232, Interface Between Data Terminal Equipment and

Data Circuit-Terminating Equipment Employing Serial Binary Data
Interchange.

• 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 D, Customer
Communication, at the end of this manual.

© National Instruments Corp. 1-1 GPIB-232CV User Manual

Chapter 1
Description of the GPIB-232CV

This chapter contains a brief overview of the GPIB-232CV, lists the
contents of your kit and optional equipment, and describes the panels of the
GPIB-232CV.

Introduction

The GPIB-232CV, shown in Figure 1-1, provides a method of connecting a
device with a RS-232 port to the GPIB, or IEEE 488, bus. The
GPIB-232CV transparently converts data between the two ports so that
control codes or special commands are not required. The GPIB-232CV
also increases the efficiency of the interface system by isolating the slower
device from the faster port with a 256 KB character buffer. This buffer is
used to offload the host computer during printer and plotter applications.

Figure 1-1. The GPIB-232CV

Description of the GPIB-232CV Chapter 1

GPIB-232CV User Manual 1-2 © National Instruments Corp.

The GPIB-232CV is capable of interfacing either a GPIB Controller or a
GPIB device to a computer or instrument with a RS-232 port. It can be
used to interface a GPIB device to a computer with a RS-232 port or to
connect a RS-232 device such as a printer or plotter to a GPIB network.
Data transfers in either direction are possible at all times.

What Your Kit Contains

Your kit should contain the following components:

Component Part Number

One of the following boxes:

• GPIB-232CV (256 KB RAM - 115 VAC) 776174-02

• GPIB-232CV (256 KB RAM - 230 VAC) 776174-32

GPIB-232CV User Manual 320109-01

Chapter 1 Description of the GPIB-232CV

© National Instruments Corp. 1-3 GPIB-232CV User Manual

Optional Equipment

Component Part Number

Rack mount Kit:

Single (1 unit) 180480-01
Dual (2 units) 180480-02

RS-232 Shielded Cable, Compatible with IBM PC

DTE to DTE - 1 m 181074-10
25-pin male D-sub to 9-pin female D-sub

Double-Shielded GPIB Cables:

GPIB Type X2 Cable – 1 m 763061-01
GPIB Type X2 Cable – 2 m 763061-02
GPIB Type X2 Cable – 4 m 763061-03

The GPIB-232CV Front Panel

The front panel of the GPIB-232CV is shown in Figure 1-2. The power
switch and six light-emitting diodes (LEDs) are mounted on the
GPIB-232CV front panel.

GPIB-232CV

IEEE 488 RS-232 CONVERTER

POWER READY TALK LISTEN BUSY FULL

Figure 1-2. The GPIB-232CV Front Panel

Description of the GPIB-232CV Chapter 1

GPIB-232CV User Manual 1-4 © National Instruments Corp.

The LEDs show the current status of the GPIB-232CV at all times.
Table 1-1 describes each LED.

Table 1-1. LED Descriptions

LED Indication

POWER Indicates that power to the unit has been applied and the

ON/OFF switch is in the ON position.

READY Indicates that the power-on self-test has passed successfully

and the unit is ready to operate.

TALK Indicates that the GPIB-232CV is configured as a GPIB

Talker.

LISTEN Indicates that the GPIB-232CV is configured as a GPIB

Listener.

BUSY Indicates that the GPIB-232CV is currently accepting serial

data. Each serial character received toggles the status of
the BUSY LED.

FULL Indicates that one of the GPIB-232CV data buffers is full.

This is not an error condition, but is merely a signal that
bus performance may be reduced to the speed of the slower
interface.

Chapter 1 Description of the GPIB-232CV

© National Instruments Corp. 1-5 GPIB-232CV User Manual

The GPIB-232CV Rear Panel

The power cord, serial cable, and GPIB cable connections are on the rear
panel. Figure 1-3 shows the rear panel of the GPIB-232CV.

Figure 1-3. The GPIB-232CV Rear Panel

Description of the GPIB-232CV Chapter 1

GPIB-232CV User Manual 1-6 © National Instruments Corp.

The RS-232 Connector

The RS-232 port on the GPIB-232CV is configured as a DTE (Data
Terminal Equipment) and uses a standard 25-pin shielded D-subminiature
female connector with screwlock assemblies. The RS-232 connector will
accept standard 25-pin D-subminiature male connectors. A diagram of the
serial connector and the signals supported is shown in Figure 1-4. For more
information on the RS-232 signals refer to Appendix B, Interfacing to a
Serial Device.

NC
NC

NC
NC
NC

DTR

NC
NC
NC
NC
NC
NC

NC
NC

NC
NC

NC
NC
GND
NC
CTS
RTS
RXD
TXD

GND

12

4

3

5

67

8

9

10111213

141516171819202122232425

Figure 1-4. The RS-232 Connector and Signal Designations