Problem with filters.

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Hugo_8

3 Mar 2012
Posts: 2

Hello,

I am trying to implement a filter over the Simple Scope program. The idea is to filter the signal that the program receives from Channel B and then show the Power spectrum of it. For some reason the filter is not working well. I have checked the Power Spectrum of the signal before filtering it and it is correct.

I attached the VI.
Could you give me any suggestions?

Thanks,

Hugo.

Attached Files

Simple scopeModified2.vi (1.5MB)

bartschroder

4 Mar 2012
Posts: 478

Hello Hugo,
I looked into the labview in your diagram, and have to admit finding it hard to understand. There were several errors in the wiring to the filters (wiring the sample rate to the lower cutoff frequency, and the sample rate was not correctly generated).

In the end, I made a new VI called ‘Freq Selective Voltmeter.vi’, which I believe does what you want. Simply wire it into play in Simple Scope as:

I attach the vi.
You can wire terminals to define the centre frequency, and filter numbers for the vi if you want to programmatically control these.

Good luck with this.

Kind regards

Bart Schroder
Cleverscope

Attached Files

Freq Selective Voltmeter.vi (56.4KB)

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