Reference information for remote control
R&S
®
SMM100A
1036
User Manual 1179.1341.02 ─ 05
A.3.1
GPIB-Bus interface
Pin assignment
Figure A-1: Pin assignment of GPIB-bus (IEEE 488) interface
Bus lines
●
Data bus with 8 lines D0 to D7:
The transmission is bit-parallel and byte-serial in the ASCII/ISO code. D0 is the
least significant bit, D7 the most significant bit.
●
Control bus with five lines:
IFC
(Interface Clear): active LOW resets the interfaces of the instruments connec-
ted to the default setting.
ATN
(Attention): active LOW signals the transmission of interface messages, inac-
tive HIGH signals the transmission of device messages.
SRQ
(Service Request): active LOW enables the connected device to send a ser-
vice request to the controller.
REN
(Remote Enable): active LOW permits switchover to remote control.
EOI
(End or Identify): has two functions in connection with ATN:
–
ATN=HIGH active LOW marks the end of data transmission.
–
ATN=LOW active LOW triggers a parallel poll.
●
Handshake bus with three lines:
DAV
(Data Valid): active LOW signals a valid data byte on the data bus.
NRFD
(Not Ready For Data): active LOW signals that one of the connected devi-
ces is not ready for data transfer.
NDAC
(Not Data Accepted): active LOW signals that the instrument connected is
accepting the data on the data bus.
Hardware interfaces
