Where to Ground Shielding Cable for DAQ Device

Updated May 13, 2024

Reported In

Hardware

  • PXIe-4340
  • PXI Displacement Input Module

Issue Details

I have a cable running from a DAQ device to a sensor. The cable has a shielding wire. What am I supposed to do with this wire?

Solution

This question is answered in the Field Wiring and Noise Considerations for Analog Signals document, under the "Capacitive Coupling" section. If the sensor is grounded, use that ground, and don't connect the wire on the side of the measurement device. If the sensor is not grounded, leave that wire disconnected and connect it on the DAQ card side to the card's ground. This ground is likely called AIGND or something similar.

Additional Information

Be sure not to ground the cable on both sides - this will create a ground loop between the sensor and DAQ card and could damage one of them.