Abstract: A central station system in which the central station is normally connected to one or more remotely located bridging points by a dedicated communication path, each bridging point having a plurality of output ports to which one or more remote station devices are connected. In response to address signals generated by the central station, abridging point connects an identified output port to the dedicated communication path to allow communication between the associated remote stations and the central station. All other output ports are electrically isolated from the dedicated communication path. In the event of failure of the dedicated communication path, apparatus is provided for establishing an alternate communication path through the commercial telephone network. The system is highly immune to tampering and other forms of failure because of automatic decision-making capabilities of the bridging point and other features of the apparatus.