Abstract: A control system including a programmable multiple channel digital controller which is operable to generate control signals which are transmitted over electrical power lines of a building complex for enabling receivers associated with functional devices for controlling the operation of functional devices, the transmitter being operable to transmit control signals during selected ones of a plurality of data channels which define a data frame, and in one embodiment, different ones of the receivers are programmed to respond to control signals transmitted in different data channels for controlling the associated functional device. In another embodiment, the transmitted control signals are coded to represent an address of one or more of the receivers and a control command, each receiver comparing its address with the transmitted address, and the addressed receiver effecting the control function represented by the control command.

Abstract: An alarm transmission system for transmitting alarm and status information from a secured area to a monitoring area over a transmission line includes a code source in the secured area which provides a line security code for securing the transmission line, an alarm source which modifies the line security code in the event of an alarm condition, and a data selection network which enables preselected bits of the line security code and a further bit representing the access/secure status of the secured area to be transmitted to the monitoring area during preassigned time slots for comparison at the monitoring area with corresponding bits of a reference code provided by a reference code source, and an access/source status bit to permit an alarm to be indicted when one or more of the compared bits differ.