I have an NI USB6212 the BNC style DAQ and am trying to read in the voltage from a gas analyzer. I keep seeing these voltage spikes in the data stream though, and they are not present when I plug the voltage out from the analyzer to just an oscilliscope. I attached some screenshots of what I am seeing. All this vi has in it, is a daq assistant set to read voltage at 100 samples per second for various rates, 10Hz, 100Hz, 1kHz. you can best see the spikes on the 1kHz or 10hz graph. I have the analyzer connected through a UPS to try and get rid of some line noise but that shouldnt be a problem anyway if it did not show up on the scope.
I should also mention that this unit was just evaluated by the manufacturer and they saw some spikes but none as high as this so it must be a problem at the labview/daq end.