RS-232/485 to 4-port RS-485 Hub

  • Support 1 RS-232/485 upper computer port, and 4 RS-485 lower computer port
  • Each lower computer port can connect to 32 standard RS-485 devices(nodes)
  • Support cascading of multiple SW4485I, up to 256 RS-485 buses
  • Automatic serial port signal rate detection, support 300bps~115200bps serial port baud rate, zero-delay conversion
  • Serial port provides 15kV electrostatic protection and 2kVAC isolation protection
  • Unique automatic detection and alarm of RS-485 signal reverse connection


SW4485I is a RS-485 bus split HUB designed for addressing RS-485 large scale system needs in complex electromagnetic field. It supports up to 115.2kbps transmission rate and adopts bidirectional transparent transmission that could split 1 RS-485 bus into 4 RS-485 buses or transparently transmit any RS-485 signal to the RS-485 bus or RS-232 of the upper computer. Each RS-485 port of this product’s lower computer is equipped with reverse connection fault alarm and protection function, which has improved the reliability of current RS-485 network remarkably and shortened the time of maintaining network effectively. In order to ensure the safety and reliability of data communication, RS-485 ports of this product are all provided with 2kVAC isolation voltage protection, level-4 electrostatic protection and level-2 radiated immunity protection which could prevent lightning strike, electrostatic and radiated interference. It’s safe and reliable, and appropriate for outdoor engineering application.

SW4485I also provides RS-485 bus star connection. User could easily improve RS-485 bus structure and split network segment. Reasonable utilization of SW485I enables you to design a unique and reliable RS-485 system. SW4485I adopts EMC protection and supports Din-Rail mounting and -40℃~75℃ wide operating temperature range, which can meet the requirement of different scenes.

Serial Port  

Standard: EIA RS-232C, RS-485

Serial port quantity: upper computer port, 1 RS-232/485 serial port;

lower computer port, 4 RS-485 serial ports

RS-232 signal: TXD, RXD, GND

RS-485 signal: D+, D-, GND

Baud rate: 300bps~115200bps

Data bit: 5bit, 6bit, 7bit, 8bit

Stop bit: 1bit, 1.5bit, 2bit

Check bit: None, Odd, Even, Mask, Space

Interface form:  upper computer port (RS-232/485), adopts 5-pin 5.08mm pitch terminal blocks; lower computer port(RS-485), adopts 10-pin 5.08mm pitch terminal blocks 

Transmission distance: RS-232 serial port, 15m;RS-485 serial port, 1200m

Direction control: RS-485 adopts automatic data flow control technology, which could detect and control the direction of data flow

Load capacity: RS-485 supports 32-point polling environment

Interface protection: 15KV electrostatic protection, 2kVAC isolation protection





Power Supply Indicator, serial port data sending/receiving indicator, lower computer serial port indicator







12~48VDC, 3-pin 7.62mm pitch terminal blocks;

Power supply supports non-polarity





No-load: 0.696W@24VDC

Full-load: 0.696W@24VDC





Operating temperature: -40~75℃

Storage temperature: -40~85℃

Relative humidity: 5%~95%(no condensation)





Housing: metal,  IP40 protection

Installation: DIN-Rail mounting

Dimension (W x H x D): 35mm×110mm×95mm

weight: 384.8g


Industrial Standard  

IEC 61000-4-2 (ESD, electrostatic discharge), Level 4

Air discharge: ±15kV

Contact discharge: ±8kV


IEC 61000-4-3 (RS, radiofrequency electromagnetic radiated immunity), Level 2

Test level: 3V/m

Frequency range: 80MHz-1GHz


Shock: IEC 60068-2-27

Free fall: IEC 60068-2-32

Vibration: IEC 60068-2-6






3 years


Available Models RS-232/485  RS-485 Power Supply
SW4485I 1 4 12~48VDC