Title: Hardware Installation Guide.pdf
282 — revision 6Hardware Installation GuideICM upstream wiringTo enable RS-485 termination, install jumper on pin header J22 (on the last unit on the communication line).Notes: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 [1219m]). 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.49.4Control Output Wiring