The ISIS-E Extender module provides 5 safety switch inputs to an ISIS control unit (ISIS-2 or ISIS-4). Multiple ISIS-E extender modules can be connected together into one system, making it possible to monitor large numbers of machine guards, or to add gates to an existing system at a later date. The ISIS-E requires 24 VAC/DC supply and a simple 2-wire connection from the ISIS-E to any active ISIS safety switch input. LED indication is available from all gate switches showing guard status.