Thank you for your post! I have several questions that may help us to understand why the FM Deviation measurement is not what you are expecting. I have listed these questions below:
What is your overall application?
Is the 5600 part of a larger system? Typically, performing an FM Deviation requires a Signal Analyzer, or a Vector Signal Analyzer. The 5600 itself is just a downconverter.
What is the signal you are performing this FM Deviation on? From the description, you gave, it sounds like an FM signal, but the post states that you are using an AM Signal.
Additionally, looking through the code you attached, you are looking to perform an EVM measurement. Out of curiosity, are you looking for the EVM of the modulated signal coming in? Or the modulated signal with FM deviation?
I hope these questions help to narrow down what is going on and get your code running successfully!
The equipment utilized is PXI-5600 & PXI-5142, The incoming signal is VHF band 118MHz to 137MHz AM Modulated 70% @ 1KHz. I'm conducting RTCA/DO-186B section 2.3.11.c testing; the frequency deviation due to unwanted frequency modulation of the carrier shall not exceed +/- 3KHz. I'm not conducting an EVM measurement during this particular test.
