Simple Data Acquisition Question Please Help!

[PieterKreuk]

I am having trouble with a simple LabVIEW program.

I am analyzing two voltage inputs and right now I have the VI working so that both are analyzed at 10k Hz simultaneously and displayed in two waveform charts.  What I would like to do is write values for them at 1 Hz to an excel sheet or a text file with the time, the first value, and the second value.  Thus I would like to create an array of [time, value1, value2] and export that to a line in a text file, that I can then analyze later in excel.  I want this to continue for the duration of the program. Also, if it is possible to have LabVIEW generate statistics of such an array once the user ends the loop, that would be even better.

I can only assume that this isn't too complicated, but I have never done any data exporting and just a quick explanation will probably save me soo much time.  Any help would be great, even if it's just to say "use this function".  Thanks so much.

Pieter

[PieterKreuk]

Also, if I were to want to analyze this signal on the fly, how do I accomplish that?  One of the signals is a blood pressure, and I would love to be able to sample that to generate a pulse rate.

[Aaron_W. · Accepted solution]

Pieter,

Thank you for posting on the NI Forums. I was able to take an example that was similar to yours and arrange the data into the format that you were looking for. I have included a picture as well as the VI saved for LabVIEW 8.6. I took the data from the arrays that were coming in from the Read channel and manipulate it so it was in format of Time, Channel 0, Channel 1. Hope this helps and let me know if you have any questions. Thanks!

[PieterKreuk]

We are working with rats and mice and I was wondering if there is an available waveform analysis tool that could generate a heart rate on the fly by analyzing the frequency of the blood pressure pulses.  Will this require a constantly resetting threshold?  Their pulse rates are fast, so the 1000 samples in one second would likely catch about 10 beats.

[rpursley8]

You would have to post an example of the acquired data to get answers to that.

[PieterKreuk]

Okay, I'll do that later today.  Thanks.

[Nghtcrwlr]

Can u please save the VI in LabVIEW 7.1 format???

[Aaron_W.]

Nghtcrwlr,

I saved the VI so it will open with LabVIEW 7.1, but I don't have a DAQmx driver that support 7.1 so I was unable to verify that it opens correctly. If all else fails you could just use the JPG image to re-create the VI. Thanks!

Message Edited by Aaron W. on 07-20-2009 10:27 AM