A have just completed a structure that houses 19 pressure transducers that measures RSE signals. As I complete the wiring for this project I am wondering if the AI GND terminals are shared throughout the board? I question this because I need to determine the number of terminal blocks coming from the power supply that are necessary for the reference ground.
Ultimately: will I need a reference ground at screw terminal locations 3,6,9,12,14,19,22,25,28,30,35,38,41 and 44?
OR: if they are shared throughout maybe I only need a reference ground at screw terminals 3 and 35?
As mentioned they are internally connected (but with small traces so do not allow high currents to flow between them by creating ground loops or trying to connect two "Earths" with potentially different ground potentials together through them. Those AI grounds are meant to be used to connect things like cable shielding for your sensors that are not grounded in other ways, or the reference signal of the sensor itself if the sensor has no ground/earth connection itself. That excludes referencing of non-isolated sensors that are already connected to ground through their (metal)-housing. If your sensor is however electrically isolated you need to reference its common signal to the AI GND pin to avoid floating signals.
Thank you for the reply and I apologize for my lack of knowledge to DAQ units, that is why I am here after all. My cables shielding is grounded off via terminal blocks to earth ground.
So I am correct in saying that all I would need it 1 reference GND signal to accommodate all 19 of these sensors?