Annexes
R&S
®
ZNA
1648
User Manual 1178.6462.02 ─ 20
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.
The R&S
ZNA provides several functions to communicate via GPIB bus. They are
described in the following sections.
12.3.3.1
Interface functions
Instruments which can be controlled via GPIB bus can be equipped with different inter-
face functions. The interface functions for the R&S
ZNA are listed in the following table.
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, deaddressed
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
12.3.3.2
Interface messages
Interface messages are transmitted to the instrument on the data lines, with the atten-
tion line being active (LOW). They serve to communicate between controller and
instrument.
Interfaces and connectors