I'm sure this is a very basic question, rest assured I'm not in the PLC business, just wondering about applying one. The PLC manual says common terminals are common and the drawing enclosed shows them not used. There is also IN + and IN - 1) Are the “In-” terminals effectively isolated from one another so I can connect channel 1, 2, and 3 to different parts of the same circuit that are at different potentials (i.e. would the enclosed picture work?) (I understand maximum input voltages, etc, the drawing is just for concept.) 2) Curious, what are Common terminals used for then? Thanks for your assistance! Gord