Abstract: An interface circuit of a sub-system of a distributed fire detection system having a plurality of sub-systems, wherein the plurality of sub-systems are in communication with each other in a loop configuration to allow data signals to be routed between said sub-systems. The interface circuit connects the internal components of a sub-system to the external bus line connecting all components via at least three input/output ports. It comprises hardware logic components, namely switches and switch controllers listening for incoming data and opening or closing said switches to cause disconnection and connection between said input/output ports accordingly, thereby allowing the routing of data signals to one or more of the other input/output ports. The simpler configurations replaces a routing processor.

Abstract: An interface circuit of a sub-system of a distributed fire detection system having a plurality of sub-systems, wherein the plurality of sub-systems are in communication with each other in a loop configuration to allow data signals to be routed between said sub-systems. The interface circuit connects the internal components of a sub-system to the external bus line connecting all components via at least three input/output ports. It comprises hardware logic components, namely switches and switch controllers listening for incoming data and opening or closing said switches to cause disconnection and connection between said input/output ports accordingly, thereby allowing the routing of data signals to one or more of the other input/output ports. The simpler configurations replaces a routing processor.