A method for operating a photoelectric barrier as well as a photoelectric barrier with at least one first and one second optoelectronic machine guard. The first optoelectronic machine guard has a first transmitter and the second optoelectronic machine guard has a second transmitter and receiver unit. The transmitters of the first optoelectronic machine guard are successively activated during a run of a first cycle so as to emit a single light pulse, and the transmitters of the second optoelectronic machine guard are successively activated during a run of a second cycle so as to emit a single light pulse. The cycles occur substantially simultaneously.
A duration of the first cycle is lengthened or shortened by the duration of a first phase offset ΔA and that the duration of the second cycle is lengthened or shortened by the duration of a second phase offset ΔB.