Access control system especially for motor vehicle, has base unit that selects registration time window duration depending on appropriate transmission delay period for relevant group request signal

摘要

The system carries out identification transmitter registration at the start of a communications process. Each identification transmitter returns a specific response signal to a base unit if it has previously received a group request signal. The base unit selects a transmitter in a suitable time window and communicates with it. The registration time window duration is selected depending on an appropriate group request signal transmission delay. The system has a base unit (2) that carries out an identification transmitter (20) registration process at the start of a communications process involving sending a group request signal. Each identification transmitter returns a specific response signal to the base unit if it has previously received the group request signal. The base unit selects a prioritized identification transmitter using criteria in a suitable time window and communicates with the selected identification transmitter. The base unit selects the duration of the registration time window depending on the appropriate transmission delay period for the relevant group request signal. An Independent claim is also included for a method of communicating between a base unit and several identification transmitters of an inventive system.