To use the Fire-Cryer Plus sounders in their multi message mode it is necessary to send commands to the sounders to insruct them which of the seven messages they should broadcast. 

This is achieved by introducing the Multi-Message Switching PCB. It is ideally suited to new compact conventional single zone buildings, complex networked sites with man zones as well as retrofitting to existing systems. With the addition of interfaces such as the Hochiki CHQ-DSC and the Apollo SCC the Fire Cryer Plus can be successfully installed on addressable loops. 

Each MMSP has two 2amp sounder circuits which are monitored by the Fire Alarm Control Panel. The MMSP has a number of inputs for switching the auxilliary messages either from the keypad (if fitted) or external inputs, such as a relay, keyswitch, IO unit, call point or similar. Two of the 6 auxilliary inputs can be configured as monitored inputs, providing the opportunity to include panic alarms and terrorist or bomb alerts.