National Instruments GPIB-COM

Operation of the GPIB Appendix C

GPIB-COM User Manual C-6 © National Instruments Corporation

Figure C-3. Star Configuration of GPIB Devices

The standard connector is the Amphenol or Cinch Series 57 MICRORIBBON or AMP CHAMP

type. An adapter cable using non-standard cable and/or connector is used for special interconnect

applications.

The GPIB uses negative logic with standard TTL logic levels. When DAV is true, for example, it

is a TTL low level (≤ 0.8 V), and when DAV is false, it is a TTL high level (≥ 2.0 V).

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