Having distortion in sine wave in Fpga node in MyRio

[Aysha_shakeel]

Hi 

I am taking 50Hz 1 volt p-p signal in Fpga Target MyRio. I do get a good wave form at 1 Hz but as I increase the frequency my waveform gets distorted. I have also used time loop (flat sequence) but the output wave is very slow take minutes to execute. I want to run my vi faster what other option on Fpga target MyRio do i have in terms of controlling sampling rate. 

kindly help i am completely new to Labview and MyRio

Regards  

[GerdW]

Hi Aysha,

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@Aysha_shakeel wrote:

I am taking 50Hz 1 volt p-p signal in Fpga Target MyRio. I do get a good wave form at 1 Hz but as I increase the frequency my waveform gets distorted. I have also used time loop (flat sequence) but the output wave is very slow take minutes to execute. I want to run my vi faster what other option on Fpga target MyRio do i have in terms of controlling sampling rate. 

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What is a "time loop (flat structure)"?

Why don't you attach your VI - or even better the whole project as ZIP? (Including the lvproj file is important as it contains definitions related to your myRIO target!)

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@Aysha_shakeel wrote:

kindly help i am completely new to Labview and MyRio

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Did you already take the "Training resources" offered in the header of the LabVIEW board?

Did you learn about basics of RT and FPGA programming with LabVIEW?

[Aysha_shakeel]

I have gone through the resources and found the time loop is solution foe this problem.

https://zone.ni.com/reference/en-XX/help/371599P-01/lvfpgaconcepts/using_timing_functions/

from this link. but it doesn't seem to help me out. I continuously get distortion on 20 mili sec and on 200 mili sec my system seem to work fine but it gets really slow. I have attached the VI trying to do carrier wave PWM modulation using MyRio Fpga target.

Regards 

[GerdW]

Hi Aysha,

you still forgot to include your code/project…

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@Aysha_shakeel wrote:

I have gone through the resources and found the time loop is solution foe this problem … but it doesn't seem to help me out.

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So your "solution" is no solution at all!?

Again: Please attach your code when you have problems with your code!

[Aysha_shakeel]

Regards 

[Aysha_shakeel]

I am using function generator and Fpga node to get 50Hz 1 volt p-p signal

Regards

[Bob_Schor]

You need to attach all of your code.  To develop with a myRIO, you must have a LabVIEW Project.  It should be the case that all of the VIs that you are using in your Project exist inside a single Folder, probably inside the LabVIEW Data folder.  Compress the Folder containing your Project (right-click the Folder, choose "Send To" and then choose "Compressed (zipped) file"), and attach that .zip file.  This will show us what you are doing that is wrong, or what you are failing to do that is necessary to sample a signal.

Bob Schor

[GerdW]

Hi Aysha,

you failed to attach the whole project, so I miss all the FPGA definitions for your target.

What's the point of that chart? The FPGA does not support any displays!

What's the setting of that "Count(msec)" control? Is it still zero when you run this VI?

[Aysha_shakeel]

I change my milisec counter to 2 mili sec-200 mili sec to get the exact sampling rate. What I am trying to achieve is PWM by comparing sine wave with the carrier. Now the issue is that the sine wave m taking at 50Hz is distorted and the results are not quite satisfying.