SCPI reading the avg power value in zero span

I would like to get the avg power value in zero span mode via SCPI command. It is the value displayed in AM vs Time centered in the bottom line.

What would be the command to use ?

There is not currently a way to extract that value. It is something I could add relatively easy (I believe) for the next release of Spike.

In the meantime, if you are retrieving the I/Q data, you can make this measurement with the equation

10*log10(mean(I^2 + Q^2));

In spoken word, calculate the linear power of each I/Q sample, I^2 + Q^2, calculate the mean of the linear powers, then take the 10*log10 of that mean.

This would give you the average power in dBm over the sample interval of your choice.

Given this, would you still be interested in a SCPI command to retrieve this value?

I look forward to your response.

Hi Andrew,

thanks for your explanation of the calculation the amplitude value from the I/Q data. Still it would be nice to fetch the value from the analyser. The workaround generates lots of data, especially if you need many amplitude values…

Yes, I would be interested to have a SCPI command to retrieve it. It makes the resulting script much more easy.

Thanks for the additional feedback!

Andrew

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