Harmonic Distortion

[RicardoRebeloo1]

I am taking measurements of acceleration, speed and rotational movement and I keep that data in a txt file. After having these measurements recorded I want to make a harmonic distortion, and find the specific harmonics / fundamental harmonics, the one that predominates.
I am using the distortion measurements function but when I press it it appears (image 1) but the problem is that it only gives me this output (image 2), do not give me a graph with frequency, why ??
If anyone can help me I appreciate it.

My output:

[RicardoRebeloo1]

 My code 

[Bob_Schor]

Please attach your code.  We need something we can edit, dissect, even run (it also might help to attach a Data File so we can see what your code does with your data).  The best way to attach the code is to compress the folder containing your LabVIEW Project and attach the resulting .zip file.  A picture (tiny!) of a small piece of your code is not so helpful.

Bob Schor

[RicardoRebeloo1]

Thank you, here are the files.

Ricardo Rebelo 

[GerdW]

Hi Ricardo,

please don't SPAM people by asking for help using PersonalMessages! This is considered "rude behaviour"…

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@RicardoRebeloo1 wrote:

I want to make a harmonic distortion, and find the specific harmonics / fundamental harmonics, the one that predominates.

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Your VI does exactly what you want to do: find the one (1) dominating harmonics value!

Your example data file contains just 4 samples per columns, so determining harmonics from them seems rather senseless…

[RicardoRebeloo1]

OK, sorry. But I am not able to obtain the results graph as shown in the figure. I used the file with only 4 data, but I used another with more data and it still doesn't work.

[RicardoRebeloo1]

OK, sorry. But I am not able to obtain the results graph as shown in the figure. I used the file with only 4 data, but I used another with more data and it still doesn't work.

[GerdW]

Hi Ricardo,

so you don't want the results of that ExpressVI (SINAD, amplitude of first harmonic), but you want that FFT plot shown as "Preview"!?

Why don't you call a FFT function in your VI?

Did you know you can convert each ExpressVI into an ordinary VI and look into its block diagram (and subVIs)? That often helps to create a subVI to its own requirements!

ExpressVIs are not made for your specific requirements, but only to fulfill the most often used requirements: this can be a huge difference…

[RicardoRebeloo1]

I want to find out which frequency predominates, that is, the fundamental harmonics.