Eliminate Risk of Contention and Data Corruption in RS-485 Communications
- Wednesday, 30 April 2014
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The RS-485 communications standard was introduced in 1983 by the Electronic Industries Alliance (EIA) as a two-wire, half-duplex, multi-drop alternative to the point-to-point RS-232 interface. (Note: RS-485 can also be wired using 4-wires to enable full-duplex communication). RS-485 uses differential signaling to allow up to 32 devices to communicate peer-to-peer at distances up to 4000 feet. In most RS-485 configurations two signals, a positive and a negative, are run as a twisted pair. Since these signals are compared to one another rather than a ground reference like RS-232, RS-485 communication is less susceptible to external noise injected on the wiring and performs more reliably in industrial environments.