Abstract: A powered communications link between a central controller and a remote substation along a conductor that includes a movable or intermittent contact interacting therebetween includes a power supply located at the central controller for supplying electrical power over the conductor to the remote substation and an electrical power storage device at the remote substation for storing the power supplied over the conductor. Data and power are multiplexed over the conductor by the central controller which periodically stops the application of power to the conductors to permit a transmitter at the remote substation to send data to the central controller. A switch at the remote substation connects the power storage device to the conductor when power is being sent and disconnects it at all other times.