R&S ESR Series

Remote Control
R&S
®
ESR
573User Manual 1175.7068.02 ─ 12
Example: Overlapping command with *OPC
The instrument implements INITiate[:IMMediate] as an overlapped command.
Assuming that INITiate[:IMMediate] takes longer to execute than *OPC, sending
the following command sequence results in initiating a sweep and, after some time,
setting the OPC bit in the ESR:
INIT; *OPC.
Sending the following commands still initiates a sweep:
INIT; *OPC; *CLS
However, since the operation is still pending when the instrument executes *CLS, forc-
ing it into the "Operation Complete Command Idle" State (OCIS), *OPC is effectively
skipped. The OPC bit is not set until the instrument executes another *OPC command.
The following list includes the commands for which a synchronization via *OPC,
*OPC? or *WAI is mandatory:
Command Purpose
INIT start measurement
INIT:CONM continue measurement
CALC:MARK:FUNC:ZOOM zoom frequency range around marker 1
CALC:STAT:SCAL:AUTO ONCE optimize level settings for signal statistic measurement functions
[SENS:]POW:ACH:PRES:RLEV optimize level settings for adjacent channel power measure-
ments
11.1.5.1 Preventing Overlapping Execution
To prevent an overlapping execution of commands, one of the commands *OPC,
*OPC? or *WAI can be used. 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
corresponding action to occur.
Table 11-5: Synchronization using *OPC, *OPC? and *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. This occurs when all pending opera-
tions 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
Remote Control - Basics