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Logging Strain Data

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I'm having a hard time controlling the sample rate for strain data when using the DAQmx for strain, which is completely identical to the signal express app for strain. For some reason setting the sample rate and size only controlls the buffer, when it is set on continuous sampling, so when I try to write the data to a spread sheet excell freaks out because I'm getting 1000 samples per second by default??? 
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Accepted by topic author Newbman

Hello Newbman,

 

Thank you for using NI forums.  What DAQ device are you using and at what rate are you trying to sample?  Some DAQ devices, especially with strain measurements, have a minimum sampling rate allowed.  There is a workaround which allows you to sample at a higher rate and then average the points so that it appears as if you were acquiring at a lower sampling rate.  This KnowledgeBase provides an example for how to implement the workaround.  Although the article does mention the 9237, the principle is still the same for any card.  The first input is the actual rate that the card will be sampling at (1kHz should usually suffice but it all depends on the actual card that you are using), and the second input is the rate at which you would like to sample at.  Try this out and let me know if you have any questions.

 

Regards,

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Hello,

 

Where can I find this example? I kinda have the same issue, i want to write to an excel file, but i cant configure the rate it writes the data into it... Can you help me? I can't find the example on the knowledgeBase.

 

With kind regards

 

Peter

 

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If you are measuring strain with a DAQ module 9237 here is a knowledge base document that tells you the valid sample rates.

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Hi,

 

Thanks for the fast reply, but euhm.. well, i'm using the 9219 system. But the problem is, if I write to excel, it logs 1000samples per second in excel. I can change this by changing the sample rate from the sample clock, but then also, my graph will show only that amount of samples, and i want my graph showing every sample. I need something that makes a sum of 10 or 100 samples and logs 1 average of these 100 or 1000 samples, every second... But i'm unable to do this , since i am a newbie at this...

 

See my VI program..

 

With kind regards,

 

Peter

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