Control system and method for controlling at least one function of an object and access control and driving authorization device for a motor vehicle

Abstract

A control system for controlling an object function includes a base station and a portable code transmitter. The base station is at the object and has a transceiver unit for transmitting an interrogation signal. The code transmitter emits a response signal with a code information item in response thereto. The base station checks an authorization of the code information item contained in the response signal. The base station and/or the code transmitter determines a time period between a transmission of a part of the interrogation signal and a reception of a part thereof obtained in reaction thereto, and compares the time period with a predefined reference time period. The base station enables the object-specific function only if the measured time period is shorter than the reference time period even if the code information item of the response signal is correct. There is also provided an access control and driver authorization device for a motor vehicle where the base station transmits the interrogation signal to the code transmitter from which checkbits are transmitted back directly to the motor vehicle, bypassing an evaluation unit. The base station measures the time period between the checkbits being emitted and received back and only accepts a response signal of the code transmitter if the measured time period is shorter than a reference time period. There is also provided a method for controlling at least one function of the object.