Contents
GPIB-140 User Manual
viii
© National Instruments Corp.
Chapter 4
Theory of Operation
............................................................................................. 4-1
Message Interpreter Layer ............................................................................... 4-2
Packet Translation Layer ................................................................................. 4-3
Link Management Layer .................................................................................. 4-3
Parallel-to-Serial Translation Layer................................................................. 4-3
Physical Layer ................................................................................................. 4-3
Appendix A
Operation of the GPIB
......................................................................................... A-1
Types of Messages ........................................................................................... A-1
Talkers, Listeners, and Controllers .................................................................. A-1
The Controller-In-Charge and System Controllers .......................................... A-2
GPIB Signals and Lines ................................................................................... A-2
Data Lines ......................................................................................... A-2
Handshake Lines ............................................................................... A-3
Interface Management Lines ............................................................. A-3
Physical and Electrical Characteristics ............................................................ A-4
Configuration Requirements ............................................................................ A-5
Appendix B
Specifications
........................................................................................................... B-1
Appendix C
Introduction to HS488
.......................................................................................... C-1
Objectives of HS488 ........................................................................................ C-1
Fast Transfer Rates ............................................................................ C-1
Compatibility with Existing IEEE 488.1 Devices ............................. C-1
No Additional Software Overhead—Automatic HS488 Detection... C-1
No Changes to the IEEE 488.2 Standard........................................... C-1
No Added Cabling Restrictions beyond IEEE 488.1 ........................ C-2
IEEE 488.1 Requirements for Higher Speed Operation
(T1 Delay
≥
350 ns) ......................................................................................... C-2
Additional HS488 System Requirements ........................................................ C-2
Sequence of Events in Data Transfers ............................................................. C-2
Case 1: Talker and Listener are HS488 Capable ............................. C-4
Case 2: Talker Is HS488 Capable, But Listener Is Not HS488
Capable ............................................................................... C-5
Case 3: Talker Is Not HS488 Capable, But Listener Is HS488
Capable ............................................................................... C-6
System Configuration ...................................................................................... C-6
Appendix D
Multiline Interface Messages
............................................................................. D-1
