National Instruments GPIB-COM - Manual (Page 8)

Contents
GPIB-COM User Manual viii © National Instruments Corporation
Line Control Register.......................................................................................... 5-8
Modem Control Register .................................................................................... 5-10
Line Status Register ............................................................................................ 5-12
Modem Status Register....................................................................................... 5-14
Programming the Serial Adapter .................................................................................... 5-16
Polling Method ................................................................................................... 5-16
Interrupt-Driven Method..................................................................................... 5-16
The GPIB-COM Controller Function............................................................................. 5-17
Appendix A
Specifications
....................................................................................................................... A-1
Appendix B
Multiline Interface Command Messages
.................................................................. B-1
Appendix C
Operation of the GPIB
...................................................................................................... C-1
History of the GPIB........................................................................................................ C-1
Types of Messages ......................................................................................................... C-1
Talkers, Listeners, and Controllers.................................................................................. C-1
System Controller and Active Controller........................................................................ C-2
GPIB Signals.................................................................................................................. C-2
Data Lines....................................................................................................................... C-3
Handshake Lines............................................................................................................. C-3
NRFD (not ready for data).................................................................................. C-3
NDAC (not data accepted).................................................................................. C-3
DAV (data valid) ................................................................................................ C-4
Interface Management Lines........................................................................................... C-4
ATN (attention)................................................................................................... C-4
IFC (interface clear) ............................................................................................ C-4
REN (remote enable).......................................................................................... C-4
SRQ (service request)......................................................................................... C-4
EOI (end or identify) .......................................................................................... C-4
Physical and Electrical Characteristics ............................................................................ C-5
Configuration Restrictions .............................................................................................. C-7