Hardware Interfaces
R&S
®
SMB100A
491Operating Manual 1407.0806.32 ─ 21
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.
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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.
Interface Functions
Instruments which can be controlled via GPIB bus can be equipped with different inter-
face functions. The interface function for the R&S SMB are listed in the following table.
Table A-1: GPIB bus interface functions
Control character Interface function
SH1 Handshake source function (source handshake), full capability
AH1 Handshake sink function (acceptor handshake), full capability
L4 Listener function, full capability, de-addressed by MTA.
T6 Talker function, full capability, ability to respond to serial poll, dead-
dressed by MLA
SR1 Service request function (Service Request), full capability
PP1 Parallel poll function, full capability
RL1 Remote/Local switch over function, full capability
DC1 Reset function (Device Clear), full capability
DT1 Trigger function (Device Trigger), full capability
GPIB Bus Interface