Hi,
I've been long time dealing with Instrumentation issues, one of many questions always in my mind is regarding the power and signal share/divide in instruments.
I’ve encountered with two types,
4-wire-instrument where power and signal connections are separated, and
2-wire instrument where power and signal shares the same conductors, and some times called Loop Powered.
While the constructions of the first type (4wire) is clear enough for me, I’ve cloudy idea of How the “2-Wire instrument” works?