Page 4 - FCC/DOC Radio Frequency Interference Compliance
FCC/DOC Radio Frequency Interference Compliance This equipment generates and uses radio frequency energy and, if not installed and used in strict accordance with theinstructions in this manual, may cause interference to radio and television reception. This equipment has been testedand found to compl...
Page 5 - Danger
Danger The GPIB-120A does not generate high voltages; however, you must use extreme cautionif your system or application can cause high voltages on the shield or logic ground of theGPIB cable you attach to the electrically isolated connector (GPIB Port B) located on therear panel of the GPIB-120A. M...
Page 6 - Contents; About This Manual
© National Instruments Corporation vii GPIB-120A User Manual Contents About This Manual ...............................................................................................................ix Organization of This Manual .........................................................................
Page 7 - Figures
Contents GPIB-120A User Manual viii © National Instruments Corporation NDAC (Not Data Accepted) ........................................................A-3DAV (Data Valid) ........................................................................A-3 Interface Management Lines ............................
Page 8 - Organization of This Manual; Conventions Used in This Manual
© National Instruments Corporation ix GPIB-120A User Manual About This Manual This manual describes how to use the National Instruments GPIB-120A bus expander/isolator. Organization of This Manual This manual is organized as follows: • Chapter 1, Introduction , contains a description of the GPIB-120...
Page 9 - Related Documentation
About This Manual GPIB-120A User Manual x © National Instruments Corporation Related Documentation The following document contains information that you may find helpful as you read this manual. • ANSI/IEEE Standard 488.1-1987, IEEE Standard Digital Interface for ProgrammableInstrumentation Customer ...
Page 10 - Description of the GPIB-120A
© National Instruments Corporation 1-1 GPIB-120A User Manual Chapter 1Introduction This chapter contains a description of the GPIB-120A, lists what you need to get started andoptional equipment you can order, and explains how to unpack the GPIB-120A. Description of the GPIB-120A The GPIB-120A is a h...
Page 12 - What You Need to Get Started; Unpacking Your GPIB-120A
Chapter 1 Introduction © National Instruments Corporation 1-3 GPIB-120A User Manual What You Need to Get Started One of the following GPIB-120A Bus Expanders/Isolators: GPIB-120A (100 to 120 VAC)GPIB-120A (220 to 240 VAC) 2.2 m, 125 VAC Power Cord (When connected to a power source, this cord connect...
Page 13 - Isolation Considerations
© National Instruments Corporation 2-1 GPIB-120A User Manual Chapter 2Connection This chapter contains information for connecting your GPIB-120A. Danger: The GPIB-120A does not generate high voltages; however, you must use extremecaution if your system or application can cause high voltages on the s...
Page 14 - Placing Your Instruments; Connecting to Hewlett-Packard Controllers; Mounting the GPIB-120A
Connection Chapter 2 GPIB-120A User Manual 2-2 © National Instruments Corporation Placing Your Instruments Identify the instruments or devices in your system that are sensitive to ground loop noise. In thenext section, Connecting the GPIB-120A , you will connect these instruments or devices to Bus B...
Page 15 - Circuitry of the GPIB-120A
© National Instruments Corporation 3-1 GPIB-120A User Manual Chapter 3Theory of Operation This chapter describes the operational theory of the GPIB-120A. This chapter assumes that youhave a basic knowledge of the GPIB. If you are a first-time user or you would like to review thebasics, refer to Appe...
Page 16 - The GPIB-120A Front Panel; Power On
Theory of Operation Chapter 3 GPIB-120A User Manual 3-2 © National Instruments Corporation The circuitry on each side of the expansion monitors local GPIB states and converts the signalsmonitored into X signals (for transmit) which drive the R signals (for receive) on the oppositeside of the expansi...
Page 17 - Data Direction Control
Chapter 3 Theory of Operation © National Instruments Corporation 3-3 GPIB-120A User Manual If a GPIB device on Bus A asserts DAV, the Bus A Source Handshake state becomes true andthe Bus B Source Handshake state becomes false. If a GPIB device on Bus B asserts DAV, the Bus B Source Handshake state b...
Page 18 - Acceptable Identification Codes
Theory of Operation Chapter 3 GPIB-120A User Manual 3-4 © National Instruments Corporation Acceptable Identification Codes Bus A and Bus B of the GPIB-120A are each capable of appearing as a GPIB device having theGPIB capabilities listed in Table 3-1. For a complete description of each code, consult...
Page 19 - History of the GPIB; Types of Messages
© National Instruments Corporation A-1 GPIB-120A User Manual Appendix AOperation of the GPIB This appendix contains a brief history of the GPIB and describes the operation of the GPIB. History of the GPIB The original GPIB was designed by Hewlett-Packard (where it is called the HP-IB) to connectand ...
Page 20 - The Controller-In-Charge and System Controller
Operation of the GPIB Appendix A GPIB-120A User Manual A-2 © National Instruments Corporation Talkers, Listeners, and Controller There are three types of GPIB communicators: Talkers, Listeners, and Controllers. A Talkersends data messages to one or more Listeners. The Controller manages the flow of ...
Page 21 - GPIB Signals and Lines
Appendix A Operation of the GPIB © National Instruments Corporation A-3 GPIB-120A User Manual GPIB Signals and Lines The interface system consists of 16 signal lines and 8 ground return or shield drain lines. The 16 signal lines are divided into the following three groups. • Eight data lines • Three...
Page 23 - Physical and Electrical Characteristics
Appendix A Operation of the GPIB © National Instruments Corporation A-5 GPIB-120A User Manual Physical and Electrical Characteristics Devices are usually connected with a cable assembly consisting of a shielded 24 conductor cablewith both a plug and receptacle connector at each end. With this design...
Page 26 - Configuration Restrictions: The Role of Expanders and Extenders; Related Document
Operation of the GPIB Appendix A GPIB-120A User Manual A-8 © National Instruments Corporation Configuration Restrictions: The Role of Expanders and Extenders To achieve the high data transfer rate for which the GPIB is designed, the physical distancebetween devices and the number of devices on the b...
Page 30 - Multiline Interface Messages
Multiline Interface Messages Appendix C GPIB-120A User Manual C- 2 © National Instruments Corporation Multiline Interface Messages Hex Oct Dec ASCII Msg Hex Oct Dec ASCII Msg 00 000 0 NUL 20 040 32 SP MLA0 01 001 1 SOH GTL 21 041 33 ! MLA1 02 002 2 STX 22 042 34 " MLA2 03 003 3 ETX 23 043 35 # M...
Page 33 - Technical Support Form
Technical Support Form ___________________________________________________ Photocopy this form and update it each time you make changes to your software or hardware, and use the completedcopy of this form as a reference for your current configuration. Completing this form accurately before contactin...
Page 35 - Documentation Comment Form
Documentation Comment Form National Instruments encourages you to comment on the documentation supplied with our products. Thisinformation helps us provide quality products to meet your needs. Title: GPIB-120A User Manual Edition Date: October 1994 Part Number: 370893A-01 Please comment on the compl...
Page 36 - Glossary
© National Instruments Corporation G- 1 GPIB-120A User Manual Glossary ___________________________________________________ Prefix Meaning Value n- nano- 10 -9 µ - micro- 10 -6 m- milli- 10 -3 k- kilo- 10 3 M- mega- 10 6 ° degrees % percent A amperes AC alternating current ANSI American National Stan...
