Abstract: A communication system includes: a master control device capable of being coupled with a conductive communications pathway of a group of conductive pathways, the master control device including a signal modulator configured to transmit a power signal and a command signal along the communications pathway by modulating an electric current supplied by a power source joined with the group of conductive pathways; and a load module capable of being coupled with the communications pathway in series with the master control device and of being coupled with a slave device, the load module configured to receive the power signal and the command signal from the master control device along the communications pathway, wherein the power signal activates the load module and the command signal directs the load module to control the slave device and to cause the slave device to take an action.