SCXI-1314 ground wire

[TechMkIII]

Hello,

 We're trying to figure out which signal name position to use for our ground wire. Should we attach the ground wires to the safety-ground? Alternately, do we even need to use the ground wire on a fullbridge gauge?

Thanks!

[Wild_man · Accepted solution]

Full bridge gauges and load cells typically have 4 wires, Signal+, Signal-, Excitation+, and Excitation- These four wires are all that are needed to recieve a reading from the gauge. 

The connections for these wires are detailed in the SCXI-1314 manual

https://www.ni.com/docs/en-US/bundle/322859a/resource/322859a.pdf

If there is a separate ground the sensor may have a shielded cable. Reference the Field guide for wiring here to read more about shield termination and noise consideration.

Field Guide for Wiring

https://www.ni.com/en/shop/data-acquisition/measurement-fundamentals/field-wiring-and-noise-consider...

In my experience where to connect the shield is a highly debated topic but my understanding is as follows.

Connect the shield to ONLY the sensor IF the sensor is grounded.

Connect the shield to BOTH the sensor and the DAQ device chassis ground IF the Sensor is floating.

[TechMkIII]

Thanks!