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Advanced Features
Using software (OPC mechanism) to serialize operations
The Power Modules of the XMP 2600 generate an internal OPC (Operation Complete)
event that informs the main controller when they have completed the current operation.
The XMP 2600 has several commands and queries that can use that OPC internal event.
One such command is the *WAI command. The *WAI command, when inserted in the
stream of commands sent to the XMP 2600 by its controller, causes the XMP's main
controller to suspend further parsing of commands until all pending internal operations
are done (all the Power Modules have announced Operation Complete on previously
commanded operations).
The sequence of commands you should send to the XMP 2600 to achieve the same
operations serialization described for the hardware method above, is as follows:
Prepare the second operation to be performed. You may base the initiation of the second
operation on a trigger if it requires a lengthy command sequence to initiate.
1. Send the commands to initiate the first operation.
2. Send a *WAI command (or a *OPC command or a *OPC? Query).
3. Send the command to initiate the second operation.
The second operation will commence only after the first operation has completed and the
Power Module generated an internal OPC event to inform the main controller.
Controller notification of Operation Complete
The *WAI command, mentioned above, is used for internally synchronizing XMP
operations. It does not inform the remote controller when the previously commanded
operation has finished.
The *OPC command, on the other hand, will set the "opc" event bit of the "Standard
Event Status Register" when the previously commanded operation has finished. In all
other aspects, the *OPC command works the same as the *WAI command.
Using the *OPC command and the SRQ mechanism or a *STB? query enables the
remote controller to be notified when the internal OPC event occurs.
The *OPC? Query, adds to the OPC handling capabilities of the *WAI command a
response that is placed in the output queue when the internal OPC event occurs. The
remote controller can wait on a read of this reply (or periodically check for its presence)
or it can use the MAV status bit to generate an SRQ.
While the XMP's main controller is waiting for OPC events (when you
use commands like *WAI) you cannot communicate with it. Take extra
care not fill the XMP's input queue – do not send it new commands and
queries until those waiting in the input queue where parsed.
You may use the *OPC command or the *OPC? Query instead of the
*WAI command (see the "Controller notification of Operation Complete"
section, bellow).
XMP 2600 Programming Manual
Synchronization of operations
rev. 1.1
31
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