Using The *Opc? Command; Using The *Opc Command To Assert Srq - HP 53131A/132A 225 MHz Programming Manual

Chapter 3 Programming Your Universal Counter for Remote Operation
Elements of SCPI Commands
:CALC3:AVERAGE ON
:CALC3:AVERAGE:COUNT 50
:TRIG:COUNT:AUTO ON
:INIT
*WAI
:CALC3:AVERAGE:ALL?

Using the *OPC? Command

This method is useful if you want to hold off execution of the program while you
wait for the Counter to complete any pending activity. In the *WAI example
above, the line following the *WAI command is accepted by the Counter.
However, the Counter does not execute the command because of the preceding
*WAI command. If this line had been a command to address another instrument, it
would be immediately executed. If you had wanted to hold off the command to
another instrument, you would use the *OPC? command instead of the *WAI
command.
:CALC3:AVERAGE ON
:CALC3:AVERAGE:COUNT 50
:TRIG:COUNT:AUTO ON
:INIT
*OPC?
Read the Counter. The program will wait here until the Counter returns a 1.
:CALC3:AVERAGE:ALL?

Using the *OPC Command to Assert SRQ

This method is recommended when the Counter is on the HP-IB with many other
instruments, any of which can assert SRQ. The commands *OPC, *ESE 1 and
Programming Guide
Enable statistics.
Base statistics on 50 measurements.
On INIT, take 50 measurements.
Start 50 measurements.
Wait until 50 measurements are complete
before Counter executes another
command. At this point, commands could
be issued to other instruments.
Asks for the statistics. This command, will
not be executed until the 50th
measurement is complete.
Enable statistics.
Base statistics on 50 measurements.
On INIT, take 50 measurements.
Start making measurements.
Tell Counter to put a 1 in the output buffer
when 50th measurement is complete.
Ask for statistics.
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