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What is wrong with the DAQ 6221
Moshes
02-04-2010 08:00 AM
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Hello!
I was able to set my program to aquire the max voltage and P2P values, thank for the helpers.
Now, I have a very specific issue with the NI-DAQ 6221, it seems that when I stream the data to the amplitude and measurments VI and try to get the P2P, I get "0" (not boolian, a 0 value of the P2P) while getting 2V on the Max voltage. (dosen't make sense)
I looked into the belly of the amplitude and measurments VI and ran a debug, and noticed that it subtcates the max voltage from the minimum voltage to get the P2P, and that it recieves identical values in both Max voltage and Min voltage.
I have examined this further, and placed a program generated sin signal instead of the DAQ, and it works as it should, giving me the max voltage as I specify and P2P normally.
I use a signal generator that connects the scb-68 connector board, if this info will help in finding a solution.
Has anyone encountered this problem? do you know it's source and how to solve it?
Dennis_Knutson
02-04-2010 10:08 AM
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NIquist
02-04-2010 12:32 PM
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I think he meant to type 'subtracts'. In any case if your canned sin wave data is working it must be a problem with the data coming in from the DAQ. Probe it or set up an indicator (graph) to view it before it goes into the measurement VI. You probably have a DAQ parameter configured wrong.
As Dennis said, posting your code will help us help you.
tbob
02-05-2010 01:09 PM
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If your max and min values are the same, it means you are sending (or acquiring) a DC voltage. Use an oscilloscope to verify the signal. Also, you could have the min and max input settings to the DAQ Read vi wrong. For instance, if you are reading a signal that goes from -5v to 0v, and you set your inputs as max voltage=5 and min voltage=0, you will never read the -5v level. Hence, your max read will be 0 and your min read will be forced to 0 because your input range was set wrong. I hope this makes sense.
