The EST-ISLE is both a communication module that allows integration with external systems through the RS485 protocol, and an audio signal splitter. Address Settings - Number of addresses in the range 0-F (16 addresses). Local audio input - 4 input channels on the 8-pin connector. For easier and faster connection of audio sources, Phoenix type connectors can be used. The LOCAL AUDIO IN connector (Phoenix 8-pin connector) is bridged to local audio output (RJ-45). Uput Amplifiers - RJ-45 connector for the 4-channel amplifier. Local AUDIO OUT - RJ-45 connector for input signals to the system.