:MEASure:FFT:FDMagnitude

Command Syntax

:MEASure:FFT:FDMagnitude

Query Syntax

:MEASure:FFT:FDMagnitude?

Description

The command measures the difference in magnitude between two peaks of an FFT function waveform. See :FUNCtion:FOPerator.

You can choose a peaks by using these commands:

• :MEASure:FFT:FDMagnitude:FDPFirst — Defines which of the peaks, counting from the left of the display, you want to start making FFT measurements on. A peak must exceed the Peak Level threshold to be counted as a peak.

• :MEASure:FFT:FDMagnitude:FDPSecond — Defines the second peak used for the delta FFT measurements.

• :MEASure:FFT:FDMagnitude:FPLevel — Defines the threshold an FFT peak must cross to be considered a peak. The default Peak Level is -40 dBm.

The query form of the command returns the measured value.

Measurement Ready?

To confirm that the measurement is ready to read, you can query the measurement's status:

if ('CORR' in Infiniium.query(':MEASure:FFT:FDMagnitude:STATus?')):
	measurement = Infiniium.query(':MEASure:FFT:FDMagnitude?')

If averaging is turned on (:ACQuire:SMODe AVERage), you can also confirm if the measurement result is ready by comparing the number of specified averages (:ACQuire:COUNt?) versus the number of measurement sweeps that have occurred (:ACQuire:COUNt?). The technique uses the :COUNt? common measurement query. For example,

if (Infiniium.query(':MEASure:FFT:FDMagnitude:COUNt?') >= Infiniium.query(':ACQuire:COUNt?')):
	measurement = Infiniium.query(':MEASure:FFT:FDMagnitude?')

You can also use an acquisition limit test to test that a number of waveforms or samples have completed before returning a measurement. Refer to the :LTESt:ACQuire:CTYPe command.

Querying Measurement Results and Statistics

You can query measurement results using the :MEASure:FFT:FDMagnitude? query after making the proper instance settings.

If a measurement is installed into Results table (using the :MEASure:FFT:FDMagnitude command) and you have made the proper instance settings, you can query statistics using common child queries.

Also, you can query measurement results and statistics directly from the Results table (without having to make the proper instance settings beforehand). See Querying Measurement Results and Statistics.