Photoelectric barrier for monitoring a surveillance area, said barrier comprising at least one first optical unit and at least one second optical unit, each optical unit (102, 104) comprising a plurality of transceiver elements, each transceiver element comprising at least one optical sender, at least one optical receiver and a control element, wherein said control element comprises a driver unit for driving said at least one optical sender to emit radiation and a receiver unit for sensing and evaluating electrical signals generated by said at least one optical receiver, wherein each of said control elements of the optical units (102,104) is operable to control the at least one optical sender of the corresponding transceiver element of one of the optical units (102,104) to emit radiation towards a corresponding optical receiver of the opposing optical unit (102,104), characterized in that each of said driver units of the one of the optical units (102,104) is operable to receive a first setting signal from a corresponding receiver unit of the opposing optical unit (102,104), wherein the first setting signal indicates a measured amount of incident radiation detected by the corresponding opposing optical receiver, and wherein each of said driver units of the one of the optical units (102,104) is operable to adjust an emission intensity of said corresponding optical sender of the one of the optical units (102,104) in response to the first setting signal, wherein each of said control elements of the optical units (102,104) comprise a comparator circuit for comparing the measured amount of incident radiation to at least one predefined threshold value, wherein said control elements of the optical units (102,104) are operable to transmit, in response to the result of said comparison, said first setting signal to the corresponding opposing transceiver element. each transceiver element comprising at least one optical sender, at least one optical receiver and a control element, wherein said control element comprises a driver unit for driving said at least one optical sender to emit radiation and a receiver unit for sensing and evaluating electrical signals generated by said at least one optical receiver, wherein each of said control elements of the optical units (102,104) is operable to control the at least one optical sender of the corresponding transceiver element of one of the optical units (102,104) to emit radiation towards a corresponding optical receiver of the opposing optical unit (102,104), characterized in that each of said driver units of the one of the optical units (102,104) is operable to receive a first setting signal from a corresponding receiver unit of the opposing optical unit (102,104), wherein the first setting signal indicates a measured amount of incident radiation detected by the corresponding opposing optical receiver, and wherein each of said driver units of the one of the optical units (102,104) is operable to adjust an emission intensity of said corresponding optical sender of the one of the optical units (102,104) in response to the first setting signal, wherein each of said control elements of the optical units (102,104) comprise a comparator circuit for comparing the measured amount of incident radiation to at least one predefined threshold value, wherein said control elements of the optical units (102,104) are operable to transmit, in response to the result of said comparison, said first setting signal to the corresponding opposing transceiver element.