Digital data links are suitable for remote switch monitoring applications. It provides point-to-point contact closure information over a single fiber optic cable. These are deigned to transmit contact closure data over long distances. The FOT-CC transmitter provides a closed contact signal to the FOR-CC receiver, which activates a single pole double throw relay. It provides ground loop isolation and can be used with 50/125 to 200/230 µm fiber optic cable.

Digital data links are suitable for critical safety shutdown applications. These are used to convert up to ten contact closure inputs into fiber optic signals for transmission over a single fiber optic link.  These units are commonly used for remote transmission over long distances, transmission through hazardous areas and alarm event triggering.