Academic Hardware Products (myDAQ, myRIO)

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MyDAQ ADC Characterization

I am trying to generate a ramp from 0 to 10 volts using the Analog Output, and then read those voltages on an Analog Input channel on the MyDAQ. I set the Analog Input to read ~3 million samples, with a sampling frequency of 100KHz. The expected result of my program is a histogram with 65536 bins, with 50 hits per bin. The problem I am having is that approximately every other bin has 0 hits, and the remainder are ~100 hits, which does average out to 50 hits/bin, but I need all the bins to have ~50 hits.

 

My main question is: would there be any issue with connecting the Analog Output of the MyDAQ to the Analog Input?

 

No matter what adjustments I make, including setting the Analog Output ramp to update at twice the frequency that the Analog Input takes samples, I consistently get the same results of approximately every other bin having 0 hits.

 

Any help or insight would be greatly appreciated, thank you.

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Hello,

 

Can please upload your code or some screeshots to be able to see the application? That way we can understand in a better way.

Randy @Rscd27@
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Here is a picture of the hardware setup, and one of the vi's used. The main vi is too large so I will screenshot it.

hardware

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Here is the main vi screenshot.

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Hello Kev,

 

Thanks fo the answer, can you please send me the vi. Since you are using DAQ Assitant i cannot see the configuration of it.

Randy @Rscd27@
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Thank you for your replies, can you PM me your email so I can send the VI?

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You upload the code here. Just as the screenshot

Randy @Rscd27@
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The VI is a little to big to upload, even compressed. I've uploaded it to dropbox, here is the link.

 

https://www.dropbox.com/s/6gjjn18rnwkvabi/adc3%20-%20Copy.vi?dl=0

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Hey Kev, 

 

Can you attach the ramp.vi I have a myDAQ here so maybe i can try to run it

Randy @Rscd27@
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ramp.vi is attached in the same post as the hardware picture I believe

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