Output Format; Command Used - Keysight N1911A Programming Manual

1 Power Meter Remote Operation

Output Format

The power meter has two output formats for measurement results: ASCii and
REAL. These formats are selected using the FORMat command. When FORMat is set
to REAL, the returned result is in IEEE 754 floating-point format (note that the byte
order can be changed using FORMat:BORDer) plus <LF> as an end sentinel of the
block.
The REAL format is likely to be required only for FAST mode as it reduces the
amount of bus traffic.
Units
The power meter can output results in either linear or log units. The internal units
are linear, therefore optimal performance is achieved when the results output are
also in linear units (since the overhead of performing a log function is removed).

Command Used

In Free Run mode, FETCh? must be used to return a result.
In other trigger modes, there are a number of commands which can be used, for
example, MEASure?, READ?, FETCh? Note that the MEAS? and READ? commands are
compound commands—they perform a combination of other lower level
commands. Typically, the best speed performance is achieved using the low level
commands directly.
Trigger Count
To get the fastest measurement speed the a TRIG:COUNT must be set to return
multiple measurements for each FETCh command. For average only
measurements a count of 4 is required, however, 10 is recommended. In normal
mode (peak measurements) a count of 50 is required to attain 1000 readings per
second.
70 N1911A/1912A P-Series Power Meters Programming Guide