Transponder system for the transfer of signalling information for rail-bounded vehicles
First Claim
1. A transponder system for the transfer of signalling information for rail-bounded vehicles comprising an interrogator station and a passive responder station activated by the energy of a signal received from said interrogator station, said interrogator station being provided with a pulse generator for the continuous transmission of a pulsed interrogation signal with a given carrier frequency, said responder station being provided with a frequency transposition device for the transposition of received pulses with the given carrier frequency to a harmonic of this frequency, with a modulator coupled with the transposition device, and an information source coupled to the modulator for the modulation of the frequency transposed pulses in accordance with the information to be transmitted to the interrogation station whereby the interrogator station is provided with a detector for the detection of received frequency transposed pulses, said information source being coupled via a switching circuit to the modulator, the responder station being provided with a code generator coupled via the switching circuit to the modulator for the transmission of a continuous sequence of predetermined modulated reply pulses in response to received interrogation pulses, the interrogation station being provided with a decoder connected to the detector for the identification of an uninterrupted sequence of a predetermined number of said modulated reply pulses, whereby the decoder is coupled with the pulse generator for the insertion of a predetermined starting signal in the interrogation signal after the detection of the predetermined number of modulated reply pulses, and the responder station being provided with a start signal detector coupled to the switching circuit for the transmission of a reply pulse sequence modulated in accordance with the information to be transmitted in response to the detection of a starting signal.
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Accused Products
Abstract
A transponder system with ensured synchronization for a railway signalling system, comprising an interrogating station, from which an interrogation signal is transmitted continuously, and a responder station which is energized in response to the interrogation signal and repeatedly retransmits a coded information reply signal to the interrogating station; synchronization is achieved, by starting each information transmission by means of a predetermined start signal generated in the interrogating station as a result of a predetermined bit sequence retransmitted from the responder station. In normal operation the bit sequence is generated immediately after the retransmission of a message or word and indicates the end of this message. At the start of operation when initially the inquiry station and reply unit have bad coupling to each other, the predetermined bit sequence is generated when the amplitude of the interrogating signal received in the responder station exceeds a certain threshold level for starting-up the system.
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Citations
3 Claims
- 1. A transponder system for the transfer of signalling information for rail-bounded vehicles comprising an interrogator station and a passive responder station activated by the energy of a signal received from said interrogator station, said interrogator station being provided with a pulse generator for the continuous transmission of a pulsed interrogation signal with a given carrier frequency, said responder station being provided with a frequency transposition device for the transposition of received pulses with the given carrier frequency to a harmonic of this frequency, with a modulator coupled with the transposition device, and an information source coupled to the modulator for the modulation of the frequency transposed pulses in accordance with the information to be transmitted to the interrogation station whereby the interrogator station is provided with a detector for the detection of received frequency transposed pulses, said information source being coupled via a switching circuit to the modulator, the responder station being provided with a code generator coupled via the switching circuit to the modulator for the transmission of a continuous sequence of predetermined modulated reply pulses in response to received interrogation pulses, the interrogation station being provided with a decoder connected to the detector for the identification of an uninterrupted sequence of a predetermined number of said modulated reply pulses, whereby the decoder is coupled with the pulse generator for the insertion of a predetermined starting signal in the interrogation signal after the detection of the predetermined number of modulated reply pulses, and the responder station being provided with a start signal detector coupled to the switching circuit for the transmission of a reply pulse sequence modulated in accordance with the information to be transmitted in response to the detection of a starting signal.
Specification