Discrete to Continuous.. how?

[RPalma]

Hi to all,

I'm having this problem with the signal processing, and I hope you could help me...

I have a discrete signal, that is a capturated  with a PIC controller. Now I need that this signal become a continuous signal, so I can use a lot of other VI that I can't use when I have points.
How can I transform the discrete signal in a continuous one?

Thanks in advance,

Ricardo.

[altenbach]

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@RPalma wrote:
Now I need that this signal become a continuous signal, so I can use a lot of other VI that I can't use when I have points.

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Sorry, I don't understand. There is no such thing as a "continuous signal" on a computer, you always have "points" one way or another. You can add more points e.g. by interpolation.

Is it possible that you simply want to built an array of data points from single scalar data points?

In any case, please explain your problem in a bit more detail. Whay analysis VIs do you want to use?

[RPalma]

Altenbach,

I use the "pulse measurement" to find the frequency (through the period) of my signal, that is an heart-beat. The input ("signal in"of the pulse measurements) is a 1-D array with unsigned long. When I run the code, LV returns this error:

 "error -20309 possible reason: analysis: the amplitude of the waveform is zero, so the histogram method cannot be used".

But I have a perfect graph in the waveform chart.

I thought this was the easiest way to get the beats per minute of the heart, through the frequency of the signal.

This is my problem...

Thanks Altenbach.

[altenbach]

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@RPalma wrote:
The input ("signal in"of the pulse measurements) is a 1-D array with unsigned long.

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OK, could you add an indicator to you 1-D U32 array here, run the VI once, then right-click on the new indicator and "change to constant". Now delete the rest of your code except for the graph and the pulse measurement VI

(You should end up with a very simple VI that reads from the diagram constant, displays it and will hopepfully duplicate your error code).

Save the VI under a new name (!) and attach it here.

[RPalma]

Hello again Altenbach,

Here goes the VI. Now the error is: "the input waveform size is zero".

It what was expected?

[altenbach]

Yes, maybe you did not run the VI before changing the indicator to a constant, thus it is an empty array. Your indicator must contain data first before turning it into a constant .. 😉

Of course it is possible that versao7subVI (not included with your code) gives empty arrays once in a while (e.g. in the later loop iterations). You seem to rattle through many iterations of the FOR loop at full speed, so you might easily miss early iterations that produce good data. Sorry, I don't quite understand your code.