Post Data Capture Frequency analysis

[Clubber]

Would really aprreciatesome help.

I am capturing a pulsing signal, where a pressure increases to a unknow limit, and then falls back to ambient. This process will be repeated and a number of times over 30-60 seconds. The upper limit may vary slightly with each reading. Once this data is obtained, i want to feed the data back into LabVIEW from the save file and find the average frequency of the pulses and the  average amplitude, so the data collection and the data analysis are independent of each other, as to hopefully ease the problem.

I would also like to find each peak value, and show the values in an indicator array, but this is the least of my worries and would just be a nice.

I have tried some of the functions within LabVIEW (2009), yet don't seem to be getting sensible readings.

I have attached a txt sample of the type of data i will be obtaining.

Any help is greatly appreciated.

Thanks in advance,

Oli

[johnsold]

Oli,

This Forum is to help people but we cannot do your whole job.  I don't think that is what you were asking, but since you have not told us what you have tried and what worked and what did not it is difficult to assist you.

The idea of separating the data acquisition from the analysis is good.  Are you successfully acquiring data in LV or was the data you posted from some other source?  What have you tried for the analysis?  The built in peak detector is quite good within its limitations (positive peaks, first sample is not a peak).  Perhaps you need to break the data set into segments and find each peak separately.

Please post what you have tried along with an indication of what the desired result is.

Lynn

[Clubber]

Hi Lyn,

Sorry if that is how it came across. Like I mentioned I have created the data capture code (In my code the data is generated by a sine counter).

What I would like to know is if the data captured (time vs. pressure) can be analyses using labview to deduce the average Frequency and the average height of the pressure peaks over the timed test. 

I have tried to use many different functions, which seem to work well when I generate data using 'Simulate Signal'  function and read the signal 'Live', but these same VI's don't seem to work when I use a more basic signal or when loading a saved file. The VI's I have used were : -

Tone Measurement

Extract Single Tone Information

Cycle Average and RMS

Below is a snippet of my code basic.

Thanks again for the time and help

 

[MikeParkin]

Hi Oli,

As I understand it you are just trying to get the data from the file and then begin analyzing it. Then you want to calculate some averages and peaks based on this data.

You can get the data in LabVIEW simply by using a Read from File function. I think Lynn's suggestion of the Peak Detector.VI was a good one and something I would also recommend using. With regards to finding avarages of the data maybe the Mean.VI is something you could consider.