Depends on the signal types, the extended distance ranges from 250 feet (70 m) to 4000 feet (1.2 km) on copper wire and 3 miles (5 km) to 40 miles (25 km) on optical fiber. Daisy Chain (Multi-Drop) Typically used for multi-drop RS-485 / RS-422 networks, addressable commands from the Master can be sent to all Slaves, and the addressed Slave can respond to the Master through the same wires, thus reducing the system’s costs.
The typical distance for a daisy-chain RS-485 / RS-422 network is 4000 feet (1.2 km), and with the RS-485 / RS-422 repeater, this distance can be extended by another 4000 feet (1.2 km). Star Wiring Due to the nature of the signals and the requirements of impedance matching, the RS-485 / RS-422 network must run on a linear, daisy-chain (multi-drop) configuration; however, star-wiring is inevitable in many places.