Crosstalk on NI PXI-2575

[Multiplexias]

Hi everyone,

I am currently using two NI PXI-2575 196-channels multiplexers and I have a crosstalk issue. I am using them as switch-modules (aka. demultiplexers) to deliver a pulse-signal on the COM-port (pin 173) consecutively to the other channels for calibration of some boards. Whenever I start sending pulses on the COM port, no matter if it is linked (via LabVIEW using NI SWITCH) to another port or not, I always have huge crosstalk on all the other channels.

Do you have any idea where this could come from? Before lending these multiplexers (I have not bought them yet, as I wanted to make sure that they were working the way I want them to), I have asked an engineer from NI, who told me that using them this way should be no problem.

BTW all grounds are connected (pulser, oscilloscope and chassis (NI PXI-8335). I have already tried not connecting the pulse signal to the scope to reduce it's possible impact, but it does not change anything. May that be some shielding problem?

Regards

[Matijas31]

Hi, 

http://www.ni.com/white-paper/3953/en/

You should read that, before u use the switch cards.

Maybe it's the bouncing relays.

Best regards

Matijas