noisy input on PCI-6024 card

[curvetracejohn]

I am having a problem with noise on my analog input on the NI PCI-6024 card.  I applied a low pass and stll could not get the right voltage at the input.  Am I missing anything?  Do I need to ground all of the Ai grounds, ground the other inputs?  Any advice is appreciated.

[devchander]

since you speak of AI ground, looks like you are using a Single ended mode(RSE)

I suggest you connect your Input in Differential Mode and see if the noise rejection is better.

But before that, can you tell what kind of signal are you feeding to the DAQ card??, is it a floating signal or a ground referenced signal??

then you can determine which of the following modes is best:  RSE,NRSE or Differential

http://digital.ni.com/public.nsf/allkb/1FFCBE3451ABEE09862562970059881D

http://digital.ni.com/public.nsf/allkb/D509679FFAE2764386256297005D0C9D

This links should help you

First try this basic trouble shooting. if the noise is still evident, do get back and we could suggest other techniques to remove noise