Where an SPT is connected to the data bus of an alarm panel a regular “handshake” is maintained between the two devices. If this is broken or fails, the SPT will transmit a “Panel Lost” alarm to the ARC. In all cases the Extended format will Indicate the type of panel that has lost communication with the SPT.
For example, a Galaxy panel that is disconnected from the SPT will cause a "Galaxy Panel Lost" alarm delivery to the ARC.