Abstract: A light barrier arrangement for detecting objects in an area to be monitored includes a transmitting unit comprising a predetermined number of transmitters which emit light rays, a first storage unit, and a first integrated interface unit. The light barrier arrangement further includes a receiving unit comprising a predetermined number of receivers, each receiver being aligned with an associated transmitter to receive the light rays from the associated transmitter, a second storage unit, and an second integrated interface unit. Operational parameters of the transmitters and receivers are stored in each of the first and second storage units. The first interface unit is operative to transmit the operational parameters to and receive the operational parameters from the receiving unit. The second interface unit is operative to receive the operational parameters from and transmit the operational parameters to the transmitting unit.

Abstract: A method for monitoring an entrance to a hazardous area comprising sensing a signal pattern generated by light barriers when an object passes the entrance and comparing the sensed signed pattern with at least one predetermined signal pattern. The object is admissible if the signal patterns are identical and under certain other conditions.

Abstract: A method for monitoring an entrance to a hazardous area comprising sensing a signal pattern generated by light barriers when an object passes the entrance and comparing the sensed signed pattern with at least one predetermined signal pattern. The object is admissible if the signal patterns are identical and under certain other conditions.