On the Schneider analog input module (link) we have IC, IV, IS, 0V and Earth terminals for a single channel. I've seen people connecting the signal wire from a transducer to the IC terminal and the other wire to the earth terminal. Also, I've heard that you should actually be connecting the other (reference) wire to 0V instead since the cable screen will be connected to earth too.
When using mA, where should your reference wire be connected, 0V or Earth and why? Also, is it wrong to connect the reference wire to earth, because I've seen it many times in the plant?
Any information would be really appreciated