NI DAQ Grounds Tied Together

Updated Aug 23, 2022

Reported In


  • PXI Multifunction I/O Module

Issue Details

Are the grounds on my X Series, M Series, E Series and S Series DAQ devices all tied together?


Yes, all the grounds including analog input, analog output, and digital I/O are tied together to the common ground.

However, this connection occurs after the ADC references the appropriate ground for each respective task type, so the ground line for your incoming signal connections should still be tied to the related ground (AI GND, AO GND, or DGND) or you may experience increased noise.

Additional Information

The ground lines are still tied together before being routed to the PCI or PXI ground, and thus can be damaged if there is too great a potential difference between each ground.  Before connecting multiple ground lines, take steps to ensure that the potential is the same at each ground terminal.  If this is not possible, consider taking your readings using Differential mode.  If readings are different from one ground to another on the same card, the cable or card may be damaged or the pins bent.