Programming Examples
R&S
®
ZNC
705
User Manual 1173.9557.02 ─ 13
In the present example the sweep must be completed before measurement results can
be retrieved. To prevent wrong results (e.g. a mix-up of results from consecutive sweeps)
the controller must synchronize its operation to the execution of
INITiate<Ch>[:IMMediate]
. IEEE 488.2 defines three common commands (
*WAI
,
*OPC?
,
*OPC
) for synchronization.
// 1. Start single sweep, use *WAI
// *WAI is the easiest method of synchronization. It has no effect when sent
// after sequential commands.
// If *WAI follows INITiate<Ch>[:IMMediate]... (overlapped commands), the analyzer
// executes no further commands or queries until the sweep is terminated.
// *WAI does prevent the controller from sending other commands to the analyzer
// or other devices
// Start single sweep in channel no. 1, wait until the end of the sweep
INITiate1:IMMediate; *WAI
<Continue program sequence>
// 2. Start single sweep, use *OPC?
// If *OPC follows INITiate<Ch>[:IMMediate]..., it places a 1 into the
// output queue when the sweep is terminated.
// An appropriate condition in the remote control program must cause the
// controller to wait until *OPC? returns one.
// The controller is stopped from the moment when the condition is set.
// Start single sweep in channel no. 1, indicate the end of the sweep
// by a 1 in the output queue.
INITiate1:IMMediate; *OPC?
// So far the controller may still send messages to other connected devices.
// Stop the controller until *OPC? returns one (program syntax depends
// on your programming environment).
<Condition OPC=1>
<Continue program sequence>
// 3. Start single sweep, use *OPC
// If *OPC follows INITiate<Ch>[:IMMediate]..., it sets the OPC bit in the ESR
// after the sweep is terminated.
// This event can be polled or used to trigger a service request of the analyzer.
// The advantage of *OPC synchronization is that both the controller and the
// analyzer can continue processing commands while the sweep is in progress.
// Enable a service request for the ESR
*SRE 32
// Set event enable bit for operation complete bit
*ESE 1
// Start single sweep in channel no. 1, set the OPC bit in the ESR
// after the sweep is terminated.
Basic Tasks
