Output Format - Agilent Technologies EPM-P Series Programming Manual

Power Meter Remote Operation
Getting the Best Speed Performance
Note A trigger event can be any of the following:
• The input signal meeting the trigger level criteria.
• Auto-level triggering being used.
• A TRIGger GET or *TRG command being sent.
• An external TTL level trigger being detected.
Trigger with delay
This can be achieved using the same sequences above (apart from the
second) with TRIG:DEL:AUTO set to ON. Also, the MEAS? command
operates in trigger with delay mode.
In trigger with delay mode, a measurement is not completed until the
power meter filter is full. In this way, the reading returned is guaranteed
to be settled. In all other modes, the result returned is simply the current
result from the filter and may or may not be settled. This depends on the
current length of the filter and the number of readings that have been
taken since a change in power level.
With trigger with delay enabled, the measurement speed can be
calculated roughly using the following equation:
readings/sec = speed (as set by SENSe:SPEed) / filter length
For example, with a filter length of 4 and SENS:SPE set to 20,
approximately 5 readings/sec will be calculated by the power meter.
In general, free run mode will provide the best speed performance from
the power meter (especially in 200 readings/sec mode).

Output Format

The power meter has two output formats for measurement results: ASCii
and REAL. These formats can be selected using the FORMat command.
When FORMat is set to REAL, the result returned 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 a means to
reduce bus traffic.
EPM-P Series Power Meters Programming Guide 1-73
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