Abstract: The present invention uniquely applies data communications network techniques to a security system. A series of slave transponders are coupled via a full duplex bus to a master node. The master node is coupled to other master nodes to form a network. The master node periodically polls its slave transponders to authenticate them. Each transponder has processing capability to give a distributed processing system. Each master node is a gateway which directs transmissions to the appropriate end point. The system uses an accordion-like protocol which can have fields added or deleted in a specific structure to conform the protocol to the particular message being transmitted. The protocol begins with address bytes identifying the destination followed by a control field which identifies the fields which are present. For a broadcast, rather than a point-to-point transmission, a process ID field in the protocol determines what area or function has to be addressed in all units.

Abstract: The present invention uniquely applies data communications network techniques to a security system. A series of slave transponders are coupled via a full duplex bus to a master node. The master node is coupled to other master nodes to form a network. The master node periodically polls its slave transponders to authenticate them. Each transponder has processing capability to give a distributed processing system. Each master node is a gateway which directs transmissions to the appropriate end point. The system uses an accordion-like protocol which can have fields added or deleted in a specific structure to conform the protocol to the particular message being transmitted. The protocol begins with address bytes indentifying the destination followed by a control field which identifies the fields which are present. For a broadcast, rather than a point-to-point transmission, a process ID field in the protocol determines what area or function has to be addressed in all units.