Isolation from the Chassis Ground for NI DAQ Hardware

Updated Apr 29, 2024

Issue Details

I have a Data Acquisition Module (i.e. Sound and Vibration Module, C Series Module, etc.), is it's ground isolated from the chassis ground?

Solution

Check your hardware's Datasheet under Safety Voltages and/or the device's Circuitry diagram.

In general, if a module has its ground connected directly to chassis ground it will not have any Channel-to-earth ground isolation (this information is found under Safety Voltages >> Isolation in the device's datasheet). 

Example 1: Digital Module - Isolated from Chassis Ground 

For the NI 9375 C Series Module look at the NI 9375 Datasheet . Under Safety Voltages >> Isolation, we can see there is Channel-to-earth ground isolation. Therefore, the NI 9375 is isolated from chassis ground.

Example 2: Analog Module - Not Isolated from Chassis Ground

For the NI 9234 Sound and Vibration Module look at the NI 9234 Datasheet . Under Safety Voltages >> Isolation, we can see there is no Channel-to-earth ground isolation. Also, looking under Circuitry, the diagram references the symbol for Chassis Ground. Therefore, the NI 9234 is not isolated from chassis ground but is connected directly to chassis ground.