
Annexes
R&S
®
ZNB/ZNBT
1256
User Manual 1173.9163.02 ─ 38
NDAC
(Not Data Accepted): active LOW signals that the instrument connected is
accepting the data on the data bus.
The R&S
ZNB/ZNBT provides several functions to communicate via GPIB bus. They
are described in the following sections.
10.2.3.1
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
ZNB/ZNBT 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, 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
10.2.3.2
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.
Universal commands
Universal commands are encoded in the range 10 through 1F hex. They are effective
for all instruments connected to the bus without previous addressing.
Command
QuickBASIC com-
mand
Effect on the instrument
DCL
(Device Clear)
IBCMD (controller
%, CHR$(20))
Aborts the processing of the commands just received and sets
the command processing software to a defined initial state.
Does not change the instrument settings.
IFC
(Interface Clear)
IBSIC (controller%) Resets the interfaces to the default setting.
LLO
(Local Lockout)
IBCMD (controller
%, CHR$(17))
The LOC/IEC ADDR key is disabled.
Interfaces and Connectors