Due to driver technology used for the RS-485 standard, daisy-chain wiring topology is the required method for device connection. Issue This document attempts to explain correct methods of wiring RS485 communication networks in industrial environments based on various application notes and technical articles. Environment RS485 Serial Modbus Communications Resolution1. This technical note covers some of the design requirements for creating a successful network including wiring. This guide provides practical RS-485 wiring recommendations for RS-485 controllers, helping installers and engineers avoid communication failures and ensure long-term system stability. The TIA/EIA-485-A standard requires that a termination resistor matching the characteristic impedance of the transmission media be placed at the two farthest ends of the bus. Generic RS-485 can support up to 256 "nodes" on the network, however, Modbus RTU limits the number of nodes to 247. Nodes should be connected in a daisy chain as.
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