Hello,

in my opinion is the best way you connect your building managment system via a signal conditioner with your PLC.
You have no trouble with different potentials, like Gorund etc.

Here is a example for a conditioner:

Signal conditioner - MINI MCR-2-I-I-PT - 2901999

Hope this is helpful.

regards
CaOd

Nami847

Thank you for the reply.

Does the signal deteriorate with the distance between the two PLCs?

 yes, usually there is a point in the technical data of the device, what length the wires or cables are allowed to have.

regards,