Bernstein 6900 is a fire alarm control system specified for use in buildings of all sizes and type. It is a distributed system which consists of various components, including a main control unit, individual zone modules, annunciators, door holders, and other optional accessories. The system is designed to detect the presence of heat, smoke, and other combustible elements which may be present in a building. It is able to sound alarms, and activate automatic suppression systems in the event of a fire, to help prevent and control the spread of a fire, and eventually extinguish it.