Edited RFIC Power Servo Example Results in Inaccurate Measurement

Updated Feb 5, 2020

Reported In

Software

  • RFIC Test Software

Issue Details

I set a LO Offset or some other measurement parameter when using NI Power Servo in an RFIC example and the servo result is inaccurate. Why is this?

Solution

If you change measurement parameters after configuring the power servo, then the power servo will be inaccurate. To resolve the issue, set the parameters and call niRFmx Commit before configuring the power servo. 

Additional Information

The comments in the RFIC Power Servo examples mention that you should call an niRFmx Commit before fetching the niRFSA Handle to query the IQ Rate, Downconverter Gain, and External Gain. Otherwise, the current measurement parameters might not be committed to hardware, resulting in inaccurate FPGA Power Servo settings.