Luminous signalling system for railway networks, or road networks comprising • a luminous device comprising - LED lighting means, - a dissipative dummy load for increasing the electric power absorbed by the device when the LED lighting means are emitting light, - current interrupting means configured for interrupting the flow of a current in said dissipative dummy load, - driving means configured for cyclically activating and deactivating the current interrupting means; • a power line configured for supplying power to said luminous device; • a field controller configured for - activating said luminous device by allowing a supply current to flow along the power line, - measuring, during a sampling time interval, a value of the electric power transferred by said supply current flowing along said power line, - determining an operating state of said luminous device on the basis of said value of transferred electric power, and wherein the driving means are configured for - activating the current interrupting means, so as to allow the circulation of the current through said dissipative dummy load, before the beginning of said sampling time interval, and - deactivating said current interrupting means, so as to stop the circulation of the current through said dissipative dummy load, at the end of said sampling time interval. • a luminous device comprising - LED lighting means, - a dissipative dummy load for increasing the electric power absorbed by the device when the LED lighting means are emitting light, - current interrupting means configured for interrupting the flow of a current in said dissipative dummy load, - driving means configured for cyclically activating and deactivating the current interrupting means; - LED lighting means, - a dissipative dummy load for increasing the electric power absorbed by the device when the LED lighting means are emitting light, - current interrupting means configured for interrupting the flow of a current in said dissipative dummy load, - driving means configured for cyclically activating and deactivating the current interrupting means; • a power line configured for supplying power to said luminous device; • a field controller configured for - activating said luminous device by allowing a supply current to flow along the power line, - measuring, during a sampling time interval, a value of the electric power transferred by said supply current flowing along said power line, - determining an operating state of said luminous device on the basis of said value of transferred electric power, and wherein the driving means are configured for - activating the current interrupting means, so as to allow the circulation of the current through said dissipative dummy load, before the beginning of said sampling time interval, and - deactivating said current interrupting means, so as to stop the circulation of the current through said dissipative dummy load, at the end of said sampling time interval. - activating said luminous device by allowing a supply current to flow along the power line, - measuring, during a sampling time interval, a value of the electric power transferred by said supply current flowing along said power line, - determining an operating state of said luminous device on the basis of said value of transferred electric power, and - activating the current interrupting means, so as to allow the circulation of the current through said dissipative dummy load, before the beginning of said sampling time interval, and - deactivating said current interrupting means, so as to stop the circulation of the current through said dissipative dummy load, at the end of said sampling time interval.