E54, fire alarms do not talk to BMS systems, they share no language or protocols.
A BMS system will be equipped with usually one, or more for more complex systems, I/O unit or programable interface. The cause and effects written into the fire alarms programming dictates how these units are operated and in what circumstances. These switch one or more sets of
Contacts going back into the BMS. Multiple Chanel's can be used on systems such as the gent s-quad 4 Chanel quads that can be set as relay outputs or monitored inputs, therefore giving two way communication between the two systems. And a ability to shut down certain facilities while running up others such as extract fans.
These units are addressed onto the loop and simply change state during fire conditions, no protocol required.