Embodiments relate to a transmitter and/or a receiver for a system for detecting an event which is triggered by an object crossing a monitored line. The transmitter is configured to successively transmit data packets independently of an occurrence of the event. The receiver is configured to receive successive data packets independently of the occurrence of the event. Each data packet comprises information on a number of events which occurred up to a transmission time of the data packet, wherein the transmission times of successive data packets are each located in a predetermined transmission time period.