A system for the protection of an electric line for railway signals that comprises a computerized central apparatus (ACC) connected to a plurality of peripheral posts (PP). Each peripheral post comprises at least one plant-controller electronic card (CdE), which controls a plurality of plant-interface cards (IE) that supply the plants (E) directly, via a field bus (B1), on the basis of the commands received from the plant controller and acquire the control signals from the field sensors, transferring them to the controller.