Abstract: A railway circuit for detecting the free or occupied state of the same and for sending signalling information along a railway line to a vehicle travelling along said railway line. A signal generator generates a signal with varying current modulated with FSK technique on a basis of a modulation code. The signal is supplied to a coil magnetically coupled with first and second rails that constitute the single railway circuit to induce a variable current modulated by the code on the electric circuit formed by the portions of the first and second rail short-circuited alternatively by the electric joint. The vehicle is provided with a current sensor suitable for detecting the variable current for extraction of the code and sending the signal to the driver. A signal generator generates a signal in compliance with new safety requirements to determine, with the receiver, the free/occupied state of the railway circuit.

Abstract: A railway circuit for detecting the free or occupied state of the same and for sending signalling information along a railway line to a vehicle travelling along said railway line. A signal generator generates a signal with varying current modulated with FSK technique on a basis of a modulation code. The signal is supplied to a coil magnetically coupled with first and second rails that constitute the single railway circuit to induce a variable current modulated by the code on the electric circuit formed by the portions of the first and second rail short-circuited alternatively by the electric joint. The vehicle is provided with a current sensor suitable for detecting the variable current for extraction of the code and sending the signal to the driver. A signal generator generates a signal in compliance with new safety requirements to determine, with the receiver, the free/occupied state of the railway circuit.