When the unit has been programmed for On delay and the light signal is received by the receiver probe emitted by the emitter probe, will start time counting and operate the relay on completion of the set time (ON delay). The relay will reset on power interuption or when signal gets interrupted Or
When unit is programmed for OFF delay, the relay immediately changes contact and switches ON the load when the receiver probe receives the light beam emitted by the emitter probe. As and when the beam is interrupted the time starts counting and after set time the relay reverts to original position switching off the load.
