Peak detection (threshold detector) from spreadsheets.

[Ivan899]

Hello!

I am working on VI that reads two signals, detects peaks that are above a specific treshold and then estimates time difference between these peaks in samples and in seconds.

Recently I have obtained two waveforms using an oscilloscope in a laboratory. Then I saved these two graphs in a spreadsheet in Excel format (first number is time, second is amplitude). Time difference between them is really small, just a few nanoseconds according to the oscilloscope. I think treshold should be 0.3.

My question is how to make Threshold Detector.vi read values from two excel files? Or maybe I need to use another instrument for this purpose. I am quite confused.

I attached all materials I have.

Any help is highly appreciated!

Thank you.

[Ivan899]

Here are spreadsheets that I have got.

[billko]

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@Ivan899 wrote:

Here are spreadsheets that I have got.

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First of all, those aren't Excel files.  They are text files with commas as delimiters.  This casual mistake will only cause you grief on down the road.  Please learn to differentiate.  Now to confuse you even  more, use the "Read From Spreadsheet File.vi" with comma as delimeter to parse out the information, then manipulate the data however you want.  🙂

[billko]

PS - Sorry if you have tried this already.  I am crippled with using LV 2009 on this PC so I can't open your file without you saving it as an earlier version.

[Ivan899]

I tried Read From Spreadsheet File.vi, but have not got any positive result. Probably it reads my spreadsheets, but peak detection does not work properly. When I set up any threshold in Threshold Detector.vi that is more than zero (for example, 0.01), final results turn to zero. The same occurs when indexes in Index Array  are not zeroes. 

I attached my vi saved for LV2009. Please, have a look.

Thanks.

[billko]

For some reason or other, the VI says it is saved in LV 12 (2012).  Sorry I'm causing you such pain.

[Ivan899]

🙂

Sorry. 

Hopefully this one is for LV2009..

[billko]

Sigh... it says it can't load the front panel.  I guess someone else is going to have to take the lead now.  😞

[Ivan899]

Thanks anyway..

[billko]

If no one helps you, you can always wait until I get home (8-ish) and then I can open it up the original file.  😉