The FireBus addressable products utilize an all digital communication method called the FB-AP Series Protocol that is superimposed on top to the two-wire 24VDC power to the field devices.  By combining the communication and power on the same pair of wires, the network wiring and installation costs can be minimized.

Developed and enhanced over many years with an installed base of millions of detectors using some earlier derivative of the protocol, the latest version of the FB-AP Series Protocol is capable of a much more extensive exchange of information than previous analog addressable methods and allows FireBus to add new devices with ever increasing capabilities to the FB-AP Series product lineup.  Utilizing "Pulse Position Modulation" the protocol is electrically very robust and has the ability to go long distances, up to 5000 feet, on a wide range of common wire types while maintaining a very high resistance to EMI/RFI.

Capacity: Up to 126 unique addresses are available for use on FB-AP Series networks with each address typically constituting a single smoke detector, heat detector, contact monitor or output.

Protocol Overview: The FB-AP Series Protocol operates in three different modes:  Normal, Read and Write. The "Normal" mode is identical to previous versions of the protocol and is used to query detectors for their alarm state. It also has the ability to determine if devices on the network are able to take advantage of new extended features.

The "Read" mode is used to check information stored in the non-volatile memory of each detector. It is accessed by using a simple extension to the Normal mode communication method from the Fire Alarm Control Panel (FACP) to the detector.

In the "Write" mode the FACP is able to write information to the detector by extending the communication method in the same way as in the "Read" mode.

With these three modes, the FACP can query detector status, set heat detector set-points, select response modes, set detector sensitivity as well as controlling output devices such as relays and loop based notification appliances.