National Instruments GPIB-COM Section One Introduction

© National Instruments Corporation 1-1 GPIB-COM User Manual

Section OneIntroduction

This section contains a brief description of the GPIB-COM interface and a list of its characteristics

and components.

GPIB-COM Characteristics

The National Instruments GPIB-COM is a high-performance talk/listen interface that converts data

between a standard serial port format and IEEE-488 General Purpose Interface Bus (GPIB)

format for use with IEEE-488 printers and plotters. It can be used with any serial port software

on the PC. The GPIB-COM looks like a standard serial port to the IBM PC operating system and

software. It can be used to interface IEEE-488 devices to any PC software that uses the serial

ports.

The GPIB-COM has the following hardware features:

• emulates the standard PC serial adapter interface so that no additional software is needed

• can be configured as either COM1, COM2, COM3, or COM4

• compatible with any software using the serial ports on the IBM PC and its compatibles

• transparent addressing of unaddressed Talkers and Listeners

• choice of talk-only mode for use with listen-only printers and plotters

• choice of REN mode, which operates an instrument in the remote mode

• choice of SRQ enable, which allows monitoring of asynchronous service requests

• choice of IFC mode, which sends an interface clear when the computer is powered on

Contents

Main Page Page FCC/DOC Radio Frequency Interference Compliance Preface Introduction to the GPIB-COM Organization of This Manual Related Documents Abbreviations Used in This Manual Contents Page Figures Tables Section One Introduction GPIB-COM Characteristics What Your Kit Should Contain Optional Equipment Page Page Switch and Jumper Settings Base I/O Address and Interrupt Selection Talk/Listen Modes Talk/Listen Address and Special Function Selection Page Installation Special Considerations When Using the GPIB-COM filename Page Function Description Section Three GPIB-COM User Manual 3-2 National Instruments Corporation Figure 3-1 shows a block diagram of the GPIB-COM. GPIB Figure 3-1. Block Diagram of GPIB-COM GPIB-COM Components Page Section Four Running Diagnostic Tests The GPIB-COM Test Commands -1 printer test -2 plotter test -c change COM configuration -q quit Section Five Programming the GPIB-COM The GPIB-COM Registers Transmitter Holding Register Receive Buffer Register Divisor Latch Least Significant Byte (LSB) Register Divisor Latch Most Significant Byte (MSB) Register Interrupt Enable Register Page Interrupt Identification Register Line Control Register Page Modem Control Register Page Line Status Register Page Modem Status Register Page Programming the Serial Adapter Polling Method Interrupt-Driven Method The GPIB-COM Controller Function Appendix A Specifications Page Multiline Interface Messages Hex Oct Dec ASCII Msg Hex Oct Dec ASCII Msg Message Definitions Multiline Interface Messages Hex Oct Dec ASCII Msg Hex Oct Dec ASCII Msg Appendix C Operation of the GPIB History of the GPIB Types of Messages Talkers, Listeners, and Controllers System Controller and Active Controller GPIB Signals Appendix C Operation of the GPIB National Instruments Corporation C-3 GPIB-COM User Manual Figure C-1 shows the arrangement of these signals on the GPIB cable connector. Data Lines Handshake Lines NRFD (not ready for data) NDAC (not data accepted) Page Page Page Configuration Restrictions User Comment Form