Chapter 1
19
Introduction to Programming X-Series Applications
SCPI Measurement Commands
INITiate Commands:
:INITiate:<measurement>
This command is not available for measurements in all the instrument modes:
• Initiates a trigger cycle for the specified measurement, but does not output any data. You
must then use the FETCh<meas> command to return data. If a measurement other than the
current one is specified, the instrument will switch to that measurement and then initiate it.
• For example, suppose you have previously initiated the ACP measurement, but now you are
running the channel power measurement. If you send INIT:ACP? it will change from channel
power to ACP and will initiate an ACP measurement.
• Does not change any of the measurement settings. For example, if you have previously
started the ACP measurement and you send INIT:ACP? it will initiate a new ACP
measurement using the same instrument settings as the last time ACP was run.
• If your selected measurement is currently active (in the idle state) it triggers the
measurement, assuming the trigger conditions are met. Then it completes one trigger cycle.
Depending upon the measurement and the number of averages, there may be multiple data
acquisitions, with multiple trigger events, for one full trigger cycle. It also holds off additional
commands on GPIB until the acquisition is complete.
READ Commands:
:READ:<measurement>[n]?
• Does not preset the measurement to the factory default settings. For example, if you have
previously initiated the ACP measurement and you send READ:ACP? it will initiate a new
measurement using the same instrument settings.
• Initiates the measurement and puts valid data into the output buffer. If a measurement other
than the current one is specified, the instrument will switch to that measurement before it
initiates the measurement and returns results.
For example, suppose you have previously initiated the ACP measurement, but now you are
running the channel power measurement. Then you send READ:ACP? It will change from
channel power back to ACP and, using the previous ACP settings, will initiate the
measurement and return results.
• Blocks other SCPI communication, waiting until the measurement is complete before
returning the results
If the optional [n] value is not included, or is set to 1, the scalar measurement results will be
returned. If the [n] value is set to a value other than 1, the selected trace data results will be
returned. See each command for details of what types of scalar results or trace data results
are available. The binary data formats should be used when handling large blocks of data
since they are smaller and faster then the ASCII format. (FORMat:DATA)