Abstract: A system and method for carrying a downstream optical signal and an upstream optical signal on a fiber optic link is disclosed. The system and method includes a first transceiver unit that receives an input communication signal from at least one external communication device at an electrical input port, a transmitter that converts the input communication signal into an optical signal and transmits the optical signal as an downstream optical signal on a fiber optic link, a receiver at the second transceiver unit that receives the downstream optical signal and converts the downstream optical signal into an electrical communication signal, and a first circuit in the second transceiver unit that determines whether the second transceiver couples the electrical communication signal to a two wire intercom circuit or a four wire intercom circuit.

Abstract: A switching facility has a plurality of input ports for connection to signal sources in multiple categories, each category having multiple members, a plurality of output ports for connection to signal destinations in multiple categories, each category having multiple members, and a switch fabric configurable by a control system to connect any selected input port to any unique group of one or more output ports. A control panel interacts with the control system and has a plurality of actuatable elements and a display area associated with each actuatable element for displaying a legend associated with the actuatable element. The control system is functionally connected to the control panel and is operative to change the legend associated with an actuatable element.