Filtering Waveform and FFT Power Spectrum VI

[SpeedRacerrrrr]

Hello Everybody,

I'm trying to filter a waveform before sending it to the Power Spectrum VI, but I seem to be having issues with data type and I'm hoping someone here can point me in the right direction. 

I have a VI which reads data from a txt file and allows different sampling rates.  The acquired waveform flows to the Power Spectrum VI and also to Peak Detection.  It seems like it ought to be easy to filter that waveform before sending it to the Power Spectrum VI, but each method I have tried ends up breaking something.

Can anyone offer sugguestions?

Attached is the original VI which works, an example of filtering that doesn't work, and a data file.

Thanks!

-Damon

[Perry_S]

Hi Damon,

You are really close to having everything working. There are just a few things that you need to do to fix the filter. The main issue to be addressed is that of the data types connected to the filter itself. To understand what these data types are go to LabVIEW help and search "Butterworth Filter PtByPt VI".  Also a for loop is needed to read in each data point one at a time. The for loop does this as it auto indexes the 1D array coming out of the waveform component node of the second get waveform component function. This is the node that should be connected to the data input of the filter. Please feel free to respond if you need any more help.

Regards,

Perry S.