The bottom span 4 mA expresses a minimum signal value than a broken wire.
Since the loop current never falls to zero, it can be loop powered, allowing for a two-wire circuit.
20 mA is considered an intrinsically safe signal in most locations.
Elimination of the voltage drop errors results from long wiring runs due to the constant-current feature of a current loop.
Since the loop current never falls to zero, it can be loop powered, allowing for a two-wire circuit.
20 mA is considered an intrinsically safe signal in most locations.
Elimination of the voltage drop errors results from long wiring runs due to the constant-current feature of a current loop.