9201 card problem

[ajju]

Hello Friends,

I am using Lab view 8.6 version. I have Hardware  cDAQ 9172 to acquire signals & 9201 voltage card which can measure 10 v signal. Now problem is that when i give some constant input voltage to 9201 card like 3 volt & when i check this voltage through DAQ assistant using lab view . it shows a fluctuation in the signal of 50 to 100 mv i.e signal between 2.96 v to 3.05 v.  when i am measuring output by multimeter on the pins of 9201 card it is showing constant voltage .why it is showing so much fluctuation i the signal.

Thanks

[AdnanZ]

You don't mention anything about your signal source and the sort of input configuration you are using but I am thinking that you have not grounded your signals which is resulting in some noise. I would ask you to go through the following document and be sure to have a look at Table 1: Analog Input Connections:

Field Wiring and Noise Considerations for Analog Signals