Typical Applications Convert a current signal to a pneumatic signal so a DCS, PLC, or PC-based system can control a valve or actuator. Convert pneumatic signals to current signals to interface pneumatic devices with an indicator, recorder, DCS, PLC, or PC-based system. Reduce costs by running electrical wiring to remote pneumatic devices instead of fragile pneumatic tubing. Safely send signals through hazardous areas by converting electrical signals to harmless pneumatic signals.