Vehicle together with its switch key, said bidirectional switch key and method of transmission of information from the automobile vehicle to the switch key

摘要

The assembly has a radio transceiver (2) and a radio receiver circuit (3) to exchange a hertzian infrared or a radio data signal between them. A bidirectional key periodically examines signal frames transmitted by the transceiver according to a wake-up period function of the capacity of the key`s supply battery. The transceiver emits a synchronizing signal after the emission of a wake-up signal and before transformation of information. An independent claim is also included for a method for transmitting a data signal from a transmission and reception unit of a motor vehicle towards a switch key.