METHOD FOR RECOGNIZING IDENTIFICATION MEDIA

摘要

The invention relates to a method for recognizing identification media (IM) in the communication area (K-B) of a write/read device (WR) functioning according to the principle of inductive coupling in the MHz range, wherein an antenna is used for transmitting and receiving HF signals, in addition to a circuit (S(HF)) for transmitting HF signals with a standard transmitter power output (P-HF) and a logic circuit (Pr) for evaluating communication between a write/read device and an identification medium. A short inquiry signal (ASo) consisting of several fundamental components of the HF field and having a standard transmission power output (P-HF)is periodically transmitted via a transmission path (HFo) and the antenna (At) and a response signal (ASi) is detected (2) on the antenna (At). The response signal (ASi) is compared (3) to a reference signal (RS) and a communication signal (KS) is transmitted (4) in order to recognize an identification medium (IM) in the event that the response signal (ASi) is different (3-2) from the reference signal (RS). This enables energy-saving, reliable recognition of identification media occurring in the field of communications (K-B) for subsequent communication with the write/read device, particularly with respect to battery-operated write/read devices.