3-Wire DC-Powered Isolators
These models are used to drive resistive loads (sources current). The 4-20mA output signal and DC power share a common lead which is wired directly to the PLC/DCS's internal ground.
Acromag's 340i model is ideal for applications requiring multiple isolators at a single location where all isolators share the same power supply. PLCs and DCSs usually have 24V DC power available at their input terminals.