Abstract: An alarm system has a controller which communicates over a conductive path with a remote module. An indicating device, such as an alarm bell, strobe light, audible horn or other device is coupled to the remote module and activated when a control signal is received from the controller. A rechargeable battery is provided in or adjacent the remote module, and acts as a reservoir for the power to energize the indicating device upon connection. The remote module receives charging current over the conductive path from the controller, and this current is very low, substantially less than the current level required to energize the bell, horn, or strobe. A constant power dc-to-dc converter is provided to charge the battery at the appropriate rate, while drawing a substantially lesser amount of power from the controller. Both the rechargeable battery and the indicating device are supervised, and any malfunction reported to the controller.

Abstract: A plurality of remotely located transponder units each communicate with a central station unit to provide a full array of alarm and status signals to the central station. The transponder units are capable of remotely addressing the central station unit directly, without the need for human intervention at the central station, to alter subscriber opening and closing times, passwords, and other system parameters. The transponder also permits defective zones to be shunted either from the central station or locally pending repair, testing and status checks.

Abstract: A plurality of remotely located transponder units each communicate with a central station unit to provide a full array of alarm and status signals to the central station. The transponder units are capable of remotely addressing the central station unit directly, without the need for human intervention at the central station, to alter subscriber opening and closing times, passwords, and other system parameters. The transponder also permits defective zones to be shunted either from the central station or locally pending repair, testing and status checks.