RS-485 is a serial-based multipoint communication and electrical specification for a two-wire, half-duplex, multipoint serial communications channel. RS-485 allows for lower-cost network communication because the cabling is inexpensive and supports long-distance transmission. RS-485 equipment can be controlled by a set of commands, and it is widely used in computer automation systems, including building automation, machine automation, factory automation, and other industrial systems.
Each device on an RS-485 network needs a unique address, along with matching baud rate, checksum, and parity bit settings so that communication is compatible. ICP DAS communication products, such as our repeaters and converters, include a patented self-tuner that automatically adjusts the signal. It detects the baud rate and data format automatically and controls the data-flow direction on the RS-485 network.
RS-485 supports point-to-point, multipoint, line, and bus topologies. RS-485 does not support ring topologies.
To implement a star-type topology, you can use a star wiring hub with 4 isolated RS-485 channels such as the I-7514U. Each channel on the I-7514U has its own individual driver. If you only need to branch off a few channels, the I-7513 RS-485 hub can be used. It includes RS-485 short-circuit protection, which automatically shuts off or isolates a failed communication channel. This ensures that the rest of the equipment in the system continues operating normally.
