User Manual

Chapter 5 299
One-Button Measurement Functions
MEASURE (Spectrum Analysis Mode)
One-Button Measurement Functions
Fetch Commands:
:FETCh:<measurement>[n]?
This command puts selected data from the most recent measurement into the output buffer. Use
FETCh if you have already made a good measurement and you want to return several types of
data (different [n] values, e.g. both scalars and trace data) from a single measurement. FETCh
saves you the time of re-making the measurement. You can only FETCh results from the
measurement that is currently active, it will not change to a different measurement.
If you need to get new measurement data, use the READ command, which is equivalent to an
INITiate followed by a FETCh.
The scalar measurement results will be returned if the optional [n] value is not included, or is set
to 1. 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 for handling large blocks of data since they are smaller
and transfer faster then the ASCII format. (FORMat:DATA)
FETCh may be used to return results other than those specified with the original READ
or MEASure command that you sent.
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.