Remote Control Basics
R&S
®
NRX
460
User Manual 1178.5566.02 ─ 07
Setting command:
TRIGger:SOURce INTernal
Query:
TRIG:SOUR?
Response:
INT
14.3
Command Sequence and Synchronization
A sequential command finishes the execution before the next command is starting. To
make sure that commands are carried out in a certain order, each command must be
sent in a separate command line.
As a rule, send commands and queries in different program messages.
14.3.1
Preventing Overlapping Execution
To prevent an overlapping execution of commands, you can use one of the commands
*OPC
,
*OPC?
or
*WAI
. All three commands cause a certain action only to be carried
out after the hardware has been set. The controller can be forced to wait for the corre-
sponding action to occur.
Table 14-3: Synchronization using *OPC, *OPC?, *WAI
Com-
mand
Action
Programming the controller
*OPC
Sets the Operation Complete bit in the ESR
after all previous commands have been exe-
cuted.
●
Setting bit 0 in the ESE
●
Setting bit 5 in the SRE
●
Waiting for service request (SRQ)
*OPC?
Stops command processing until 1 is
returned. Occurs when all pending operations
are completed.
Send *OPC? directly after the command
whose processing must be terminated before
other commands can be executed.
*WAI
Stops further command processing until all
commands sent before *WAI have been exe-
cuted.
Send *WAI directly after the command whose
processing must be terminated before other
commands are executed.
Command synchronization using
*WAI
or
*OPC?
is a good choice if the overlapped
command takes only little time to process. The two synchronization commands simply
block overlapped execution of the command. Append the synchronization command to
the overlapping command.
Measurements, for example, run concurrent. The order, in which the power sensors
trigger, has not to correspond to the order of the remote commands.
Command Sequence and Synchronization
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