Analog Input PCIe6341 + 2090A Same reading on 2 different channels

[IG.B]

Hello all!

I'm not sure this is the right forum for this... But still, I hope to find an answer.

First time I'm using PCIe card 6341 with 2090A BNC.

I've connected 2 channels to DC voltage source and defined to read 3 channels in LabVIEW, on the 3rd channel i'm expecting to get some noise (near ~0Vdc).

For example, channel 0 connected to 3Vdc and channel 1 to 1.5Vdc.

But, for some reason channels 1,2 show the same input value (front pannel screenshot attached):

 

Every input you guys may have, will be very much appreciated.

[GerdW · Accepted solution]

Hi IGB,

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@IG.B wrote:

I've connected 2 channels to DC voltage source and defined to read 3 channels in LabVIEW, on the 3rd channel i'm expecting to get some noise (near ~0Vdc).

For example, channel 0 connected to 3Vdc and channel 1 to 1.5Vdc.

But, for some reason channels 1,2 show the same input value (front pannel screenshot attached):

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Your expectations are wrong… 😄

You are using a MUX devices, using just one ADC for all channels. What you are seeing is explained as "ghosting"…