Compatible with Simplex 4120 Network and converts multiple 4120 network communications signals into a single fiber optic link to 1) Multiplex audio signals (analog and/or digital) AND digital communications into full-duplex transmission over a single fiber optic cable 2) Communicate from a Fire Alarm Control Panel to a Transponder, or provide 4120 Network communications 3) Provide 4120 Network communication support for Ring, Hub, and Star Topologies, and their combinations, by performing the function of a Physical Bridge without slowing data rates