COMMUNICATION SYSTEM FOR SINGLE POINT EMERGENCY LIGHTING

摘要

An emergency lighting system comprising a central monitoring and control unit, a plurality of single point lighting units and a communication system linking all of these units and being configured with a loop topology. Addressing of single point units around the loop is achieved via a protocol whereby a first address is issued by the central unit to the first unit in the loop. This first unit then stores this address as its own and increments the address number before passing it on to the next unit in the loop and so on. When the last unit in the loop finally passes its own incremented address number back to the central unit this provides the central unit with the necessary information to determine the number of single point units in the system. Each single point unit includes mains power detection means and self testing circuitry.