Identification system for rail vehicle recognition - uses enquiry and answering unit for transmission and reception of identifying signal

摘要

The interrogating unit emits two discrete frequencies which are received by the answering unit and transformed into a third frequency by a non-linear circuit. The mixed product, whose frequency is sum or difference, is provided with an identification by a suitable modulator containing the vehicle or track information. The modulated signal is transmitted by the answering unit, received by the interrogating unit and evaluated. The answering unit has a high frequency section, a digital section, and a power supply. The H.F. section has an antenna to receive the two signals (in the region of 30 GHZ) and retransmits the mixed product. The digital section has a storage unit for the vehicle identification, plus a modulator providing the identification for the mixer.