parks vector iq graph

[BIC_es]

I need to apply parks vector approach to draw an IQ graph. I was suggested by NI member to use these two vis:

"MT Downconvert Passband.vi" and "MT IQ to XY Graph.vi".

However when I try to run my code I get these errors:

"The requested sample rate is not high enough for the specified passband bandwidth. Increase the sample rate or decrease the passband bandwidth."

then, if I decrease the passband bandwidth I get:

"Failed to design downconversion filter; Try less constraining filter parameters"

The sampling rate I used was 25 kHz, the carrier freq 50 Hz, and I have 30 sec data sets.

I am attaching the vi.

Thank you very much in advance.

[Jamie_S.]

Hi There,

Please provide the TDMS file that you wish to process. The Carrier Frequency does seem very low at 50Hz, what is the data rate put on the carrier waveform?

It may be the case that the Passband is hitting 0Hz hence the function is erroring out.

My inclination is the the carrier peak is too close to the fundamental at 0Hz for the function to be able to resolve.

Best Regards

Jamie

[BIC_es]

Hi there,

Thanks for your answer 🙂

Sorry I am not sure to understand what the problem could be.

Attached the sub.vi developed to process it. Unfortunately TDMS is not a valid extension for an attachment, but it's "simply" a sine waveform, 50Hz, about +/- 24A amplitude.

Thanks!