System and method for detecting rail break/vehicle

A system for detecting a rail break or train occupancy includes a current source adapted to deliver a current to an isolated block of a rail track. A voltage sensor is coupled to the isolated block and configured to detect voltage across the isolated block. A shunt device is coupled to the isolated block and configured to receive a shunt current from the current delivered by the current source. A shunt current sensor is coupled to the shunt device and adapted to detect the shunt current flowing through the shunt device. A control unit is adapted to receive input from the voltage sensor and the shunt current sensor and to monitor a variation of the shunt current with respect to the voltage to detect the rail break or train occupancy.