I have a DT800 datataker. I am using shared terminal voltage inputs with channel pairing (1V(#), 1+V(#), 1#V(#), 1-V(#), 2V, 2+V, 2-V, etc), giving me 42 channel single ended voltage inputs. All of the returns (GND) are combined (2#, 4#, 6# etc). I have found that the AC terminal also needs to be connected to the returns for the conversion to be performed OK.

I have used shared terminal voltage inputs (without channel pairing) on other DT800s with apparent success. On these occasions I did not connect the AC terminal. Should I have connected the AC terminal?

Good morning Owain,

Yes for all voltage types the ground side should be connected to the AC. If you look at the wiring diagrams you will see a ground symbol and the note next to it tells you to connect the ground to the AC. This ensures the signals are within the common mode range.

Cheers,
Roger