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To reduce communication and data errors, terminate each end of an EIA-485 network with a resistor whose
value equals the network's characteristic impedance. Some third-party manufacturers provide a built-in
resistor that you enable or disable with a jumper. Make sure that only devices at the end of a network have
termination enabled.
EXAMPLE If an EIA-485 2-wire network's characteristic impedance is 120 Ohms, terminate one pair by
placing a 120 Ohm resistor across the Net+ and NET- connectors of the controller. Terminate the other pair
by placing a 120 Ohm resistor across the + and - connectors of the furthest third-party controller.
A solid receive light on the controller indicates a wiring or polarity problem.
To wire a third-party device
See the Integration Guide for the third-party device or protocol.
Chilled Water System Optimizer v2
Installation and Start-up Guide
17
Wiring for third party protocols
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