Patent ID: 7598872

Claim:
A method for detecting identification media within a communication range of an antenna for transmitting and receiving RF signals of a read/write unit which operates in accordance with the principle of inductive coupling of an RF field in the MHz frequency band and which has a transmitting path connected directly to the antenna, a receiving path connected directly to the antenna, a circuit for RF communication with at least one of a standard transmitting power or reduced transmitting power, and a logical circuit for evaluating a communication between the read/write unit and an identification medium, wherein a short polling signal, which contains at least one of unmodulated or force excited oscillations of the RF field, is periodically emitted with the standard transmitting power via the transmitting path and the antenna, that during the emission of the polling signal, a return signal with at least one of unmodulated or force excited oscillations of the RF field is detected at the antenna, then the return signal is compared with a reference signal, and then a communication signal is emitted for detecting an identification medium if the return signal differs from the reference signal.