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5730A
Operators Manual
Use of *OPC?, *OPC, and *WAI
The *OPC?, *OPC, and *WAI commands are used to maintain control of the order of
execution of commands that could otherwise be passed up by subsequent commands.
If an OUT command had been sent, check if the output has settled by sending the query
*OPC?. As soon as the OUT command has completed (output settled), a 1 is shown in the
output buffer. Always follow a *OPC? command with a read command. The read
command causes program execution to pause until the addressed instrument responds.
The *OPC command is similar in operation to the *OPC? query, except that it sets bit 0
(OPC for "Operation Complete") in the Event Status Register to 1 rather than sending a
"1" to the output buffer. One simple use for *OPC is to include it in a program in order
for it to generate an SRQ (Service Request). Then an SRQ handler written into the
program can detect the operation complete condition and respond appropriately. *OPC
can be used similarly to *OPC?, except the program must read the ESR to detect the
completion of all operations.
The *WAI command causes the 5730A Calibrator to wait until any prior commands
have been completed before continuing on to the next command, and takes no other
action. *WAI is a convenient way to halt operation until the command or commands
preceding it have completed.
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