3Interface Functions - Rohde & Schwarz R&S FSP Series Operating Manual

R&S FSP
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 devices connected is not ready for data transfer.
NDAC (Not Data Accepted),
active low as long as the device connected is accepting the data present on the data
bus.
8.3.1.3 Interface Functions
Instruments which can be remote controlled via the GPIB can be equipped with dif-
ferent interface functions. The table below lists the interface functions appropriate
for the instrument.
Control character
SH1
AH1
L4
T6
SR1
PP1
RL1
DC1
DT1
C0
8.3.1.4 GPIB Messages
The messages transferred via the data lines of the GPIB can be divided into two
groups:
– "Interface Messages" on page 8.4
– "Instrument Messages" on page 8.5
Interface Messages
Interface messages are transferred on the data lines of the GPIB when the "ATN"
control line is active (LOW). They are used for communication between controller
and instruments and can only be sent by the controller which currently has control of
the GPIB.
Universal Commands
The universal commands are encoded 10 - 1F hex. They affect all instruments con-
nected to the bus without addressing.
8.4
Interface function
Handshake source function (source handshake), full capability
Handshake sink function (acceptor handshake), full capability
Listener function, full capability, unaddress if MTA.
Talker function, full capability, ability to respond to serial poll, unaddress if MLA
Service request function (Service Request), full capability
Parallel poll function, full capability
Remote/Local switch over function, full capability
Reset function (Device Clear), full capability
Trigger function (Device Trigger), full capability
No controller function
Maintenance and Instrument Interfaces
Instrument Interfaces
Operating Manual 1164.4556.12 - 06