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RS485, RS485 HUB 8-ch Isolation






RS485-HUB-8P is an industrial grade isolated RS485 hub that can expand 8-ch RS485 slave ports through 1-ch RS485 master port and can realize relay, extension, and isolation functions of RS485 network, with screw terminal for power input. Rail-mount case design, easy to install, and cost-effective. It is suitable for applications like data acquisition, IoT gateway, safety & security IoT, and intelligent instrument monitoring...


Interface Standard Compliant with RS485 Standard
Physical Interface RS485 Screw Terminal
Baudrate 300~460800bps (self-adaptive)
Supported Nodes Each RS485 port supports up to 32 nodes
Communication Distance 1200m (9600bps), the higher rate the shorter distance
Operating Method RS485 two-wire (A, B), half-duplex transparent transmission
Power Supply DC 9~24V
Operating Temperature -45 ~ +85℃
Environment Humidity <95%RH
Transmission Medium Normal parallel cables/twisted-pair cables

Interface Introduction

RS485-hub-8p 08.jpg

Onboard Resource Description
+9~24V, GND Power Screw Terminal
OUT1A~OUT8A, OUT1B~OUT8B RS485 Slave Port 1~8
485A, 485B RS485 Master Port
P1~P8 RS485 1~8 Slave Port Data Receiving Indicator
RXD 485 Master Port Data Receiving Indicator
TXD 485 Master Port Data Transmitting Indicator
POWER Power Indicator

Function Description

RS485-hub-8p 03.jpg


When the master RS485 device needs to connect 8x RS485 slaves in a star connection, connect the master to the RS485-HUB-8P master port and the slaves to the RS485-HUB-8P slave port. It can prevent interference between RS485 and isolate effectively.


By connecting one end of the RS485 to the RS485 master port and the other end to any RS485 slave port, the RS485 cable is effectively isolated and protected from lightning strikes and interference. The other end of RS485 is effectively protected from damage by high voltage and strong current.


When the RS485 cable exceeds a long distance such as 1200 meters, the signal will be attenuated and interference will increase. By using RS485-HUB-8P, the communication distance can be extended.

Hardware Connection Diagram

RS485-HUB-8P 9.jpg

Outline Dimensions




It is a one-host-eight-slave device, purely hardware wiring. Three prerequisites need to be met:

  • Consistent serial port parameters;
  • The communication protocol is half-duplex, with a question-and-answer format, such as the Modbus RTU protocol;
  • Different device addresses. The RS485 slave port can connect 7 to 1 RS485 device, or it can be connected to a single RS485 bus.
  • The scan cycle time set by the program cannot be too short. Adjust the time as long as possible to ensure that it has sufficient response time.
  • Do not connect to the host's 485 interface side by side. Use handshake cascade connection, as shown in the figure below:

RS485-HUB-8P faq.png



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