PXI-6704 GROUND

[benO-IT]

Hello,

I use current and voltage outputs on a PXI-6704 board. When i use a current output, the voltage output that use the same ground has an error (impedance of connecters and cables). I can not reduce the cable length to minimize the impedance of the ground.

My questions :

• On the PXI-6704, are all grounds connected together ? (are AGND0/AGND16, ... AGND15/AGND31 connected ?)
• Can i connected the ground of my current load (0/20mA) on another ground  than the associated ground ? risk ? (example : on channel ICH17, connect the '-' of the load to AGND2/AGND18 instead of AGND1/AGND17 ?)

Thanhs.

Regards.

Benoit.

[Jean-Philippe_C]

Hello Benoit,

To answer to your question: yes, all grounds of this board are tied together.

But I would like to understand a little bit more about the issue you are currently encountering.

What do you mean with an "error"?

Also, what terrminal block and cable do you use? And what is the DAQ driver version?

Thank you.

[benO-IT]

Hello,

Error = the voltage output less than expected (0 to 3mV).

We use a cable (183432-01) + a specific cable.

We known that we must have 0,1 to 0,2 ohm on the GND (so 20 mA x 0,15 Ohm => 3mV).

We can modify your specific cable in order to have no return current in the GND associated with used voltage output.

Regards.

Benoit.