The advantage of voltage signal input is: the signal is easy to handle (you can test the "disconnection"), the disadvantage is: the long-distance transmission signal is attenuated;

The advantage of current signal input is that the voltage at the input terminal can be transmitted over a long distance without attenuation. The disadvantage is: the signal needs to be converted, which is slightly troublesome.

Both types of input have interference problems, and both need to be careful to solve the noise problem.