RS-485 Communication

LeftEthernet / Internet Based Valve Control | 4 Types of Automated Toll Road Systems Left

Date: 2015-06-09

RS-485 Communication

RS-485 is a serial based multipoint communication and electrical specification of a two-wire, half-duplex, multipoint serial communications channel. RS-485 allows for lower cost network communication as the cabling is inexpensive and transmits across a large distance. RS-485 equipment can be controlled by a set of commands. RS-485 is widely used in computer automation systems (building automation, machine automation and factory automation and other systems).

Each device in an RS-485 network needs to have a unique address and the same baud rate, checksum, and parity bit settings information so the communication settings will be compatible. ICP DAS communication products like our repeaters and converters have a patented “self-tuner” that automatically tunes the signal. It detects the baud rate and data format automatically and controls the direction of the RS-485 network.


RS-485 supports point to point, multipoint, line and bus topologies. RS-485 does not support ring topologies.

If you wish to implement a star type topology, you can use a star wiring with 4 Isolated RS-485 channels hub like I-7514U. Each channel on I-7514U has its own individual driver. If you just have a few channels you would like to branch off onto, you can use I-7513 RS-485 hub. It also has RS-485 short-circuit protection so it will automatically shut off or isolate a broken down communication channel for protection so the rest of the equipment in the system can continue operation

RS-485 Diagram

Maria Santella
Sales Manager, ICP DAS USA, Inc.
Ph.   (310) 517-9888  x105   |  Fax. (310) 517-0998

ICP DAS USA is a provider of Industrial Data Communication, Automation Control and Test and Measurement products.  We specialize in PLC hardware, Ethernet controllers, distributed I/O modules, Industrial Ethernet Switches and protocol converters.  We provide programming services, training classes and free technical support.

LeftEthernet / Internet Based Valve Control | 4 Types of Automated Toll Road SystemsLeft