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Remote Control
R&S
®
RTM20xx
250
User Manual 1317.4726.02 ─ 01
Command
Long term
Effect on the instrument
&NREN
Not Remote Enable
Enables switchover from remote control to manual opera-
tion by means of the front panel keys
&POL
Serial Poll
Starts a serial poll.
GPIB Interface Messages
Interface messages are transmitted to the instrument on the data lines, with the attention
line (ATN) being active (LOW). They are used for communication between the controller
and the instrument and can only be sent by a computer which has the function of a GPIB
bus controller. GPIB interface messages can be further subdivided into:
●
Universal commands
: act on all instruments connected to the GPIB bus without
previous addressing
●
Addressed commands
: only act on instruments previously addressed as listeners
Universal Commands
Universal commands are encoded in the range 10 through 1F hex. They affect all instru-
ments connected to the bus and do not require addressing.
Command
Effect on the instrument
DCL (Device Clear)
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) *)
Resets the interfaces to the default setting.
LLO (Local Lockout)
The LOC/IEC ADDR key is disabled.
SPE (Serial Poll Enable)
Ready for serial poll.
SPD (Serial Poll Disable)
End of serial poll.
PPU (Parallel Poll Unconfig-
ure)
End of the parallel-poll state.
*) IFC is not a real universal command, it is sent via a separate line; however, it also affects all instruments
connected to the bus and does not require addressing
Addressed Commands
Addressed commands are encoded in the range 00 through 0F hex. They only affect
instruments addressed as listeners.
Command
Effect on the instrument
GET (Group Execute Trigger)
Triggers a previously active instrument function (e.g. a sweep). The
effect of the command is the same as with that of a pulse at the
external trigger signal input.
GTL (Go to Local)
Transition to the "local" state (manual control).
GTR (Go to Remote)
Transition to the "remote" state (remote control).
Basics