Peak Detector Settings

[DanB1983]

Hi, 

I am using the Peak Detector VI in the Signal Operation Toolbox in an attempt to report the peak values in a 1D array.

The  array is shown plotted in the attached graph.

So, as I want to report the peaks which are located at 23MHz, 36MHz, 46MHz and 54MHz, I set the threshold to -90, and leave the width at 3.

However, it would seem that although the VI correctly returns single peaks for the values at 36MHz, 46MHz and 54MHz, it returns 24 seperate peaks between 22.0125MHz and 23.6625MHz for the peak at 23MHz.

If I increase the width parameter (to around 14), I can get the function to report a single peak at 23MHz.  However, this has the unwanted effect of losing all the other peaks.

Any thoughts on how I could use the function to report a single peak at each of the desired locations?

Many Thanks,

Dan

[Coq_Rouge]

Can you post the code you are using? You are perhaps using Express VIs and because you do not have any relationship to your data. You are confused about what to do. This is a very common Express VI problem. If you want the data for specific frequency bins. You just have to index an array. Here is some information for the FFT beginner.

http://zone.ni.com/devzone/cda/tut/p/id/4278

[muks]

Can you attach the values in a text file?

[DanB1983]

Here is an excerpt of the code that I am using, and a text file containing a typical FFT array.

[DanB1983]

Forgot to mention - in order to replicate my results, set the receiver tune frequency to 42.

[herrlin]

Do you have the FFT data already in a graph or data that you could share.  Im not sure if there is an easy way to load the data from the txt file.

[DanB1983]

Here,

Should now be able to read in my text file.

Dan