Title: Hardware Installation Guide.pdf
The (EIA) Electronic Industries Association standard defines RS-485 as an electrical interface for multi-port communications on a bus transmission line. It allows for high-speed data transfer over extended distances (4000 feet/1219 m). The RS-485 interface uses a balance of differential transmitter/receiver to reject common mode noise. For increased reliability over the extended distances, End-Of-Line (EOL) termination is required.RS-485 must be terminated at both ends of the RS-485 line (bus). Terminating the line provides a more reliable communication by minimizing the signal reflection and external noise coupling. Each component provided has an on-board terminator. The installer should determine which device is at the end of the communication line.EOL TerminationIntelligent System Controller32 Downstream Devices TotalEOL Termination RequiredRS-485 Multi-drop 2 or 4 wireDownstream Communications • Four 2-wire ports • Two 4-wire ports • Combination 2 and 4 wire ports