Is the order of transmitter and receiver connection in the current loop important? I have +24VDC power supply unit, PLC with current analog input and the sensor (for test case it's just 2.35kOhm resistor). If I connect it in the typical way (first diagram: PSU -> sensor -> PLC AIN) then everything works well (output = 9.2mA). But when I swap PLC AIN and the sensor (second diagram) then the output is invalid (-0.4mA)
Why is that happen? Theoretically current AIN of the PLC is just another resistor (about 250Ohm) in series in the circuit so I thought both connections should work.