These transmitters accept 4-20mA process current inputs and provide isolated 4-20mA outputs to DCS or other indicators. Each channel is isolated from the others to prevent interaction between the channels. The 4-20mA output signal is sent on the same two wires which provide power to the transmitter.
For easy trouble shooting each unit has LEDs and diagnostic test points. Power LEDs help identify open circuits in the output loop, whilst a 10Ohm precision resistor enables monitoring of the output signal without disturbing the field wiring.