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RJ45 Ethernet to 4xRS485 Serial Server Gateway

  • Brands WaveShare Code: CA-4CH-RS485-ETH MPN:
Cashback: S$2.77
Availability: 3

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Note: The model that we sell is 4-Channel RS485 to ETH with No PoE, blue colored. Some graphics in the description might show a different model but with similar specifications.


Industrial Isolated 4-Channel RS485 to RJ45 Ethernet Serial Server

4-Channel RS485 to Ethernet, MODBUS/MQTT/JSON Support, DIN-Rail Compatible Metal Case



Features at a Glance


This multi-functional device can be used as an IoT gateway or data acquisitor with a 4-channel RS585 and an Ethernet port. It is compact, easy to install, and cost-effective.


  • 4-Channel Isolated RS485 that can work independently without affecting each other simultaneously, enabling more effective data transmission.
  • Multiple functions:
    • Serial Server
    • MODBUS Gateway
    • MQTT Gateway
    • RS485 to JSON
    • and more...
  • Screw terminals for easy installation and stable power input.
  • Compatible metal case that can be mounted either on a wall or DIN-Rails.

Note: The model that we sell is 4-Channel RS485 to ETH with No PoE, blue colored as displayed below. Some graphics on the description might show a different model but with similar specifications.



Primary Function

Bi-Directional Transparent Data Transmission between 4-Channel RS485 and Ethernet



Flexible Mounting Options

Supports industrial DIN-Rail mount or wall mount



MODBUS Gateway Support

Suitable for MODBUS Networking Upgrade, can be used with specific configuration software



Multi Communication Modes

Supports TCP Server / TCP Client / UDP Multicast / UDP Mode




More flexible conversion between different protocols



When used as an MQTT gateway, the devices can upload serial data to the MQTT server by MQTT protocol, supported servers including Baidu Cloud MQTT, Alibaba Cloud MQTT, China Mobile OneNet, etc. The acquired Modbus RTU or non-standard serial data can be parsed into JSON format and packaged into an MQTT data packet for uploading.


When used as a JSON data acquisition gateway, the devices can be connected to data acquisition instruments through an RS485 connection, then acquire data automatically, convert the data into JSON format, and finally post it to the server. The acquired data supports Modbus RTU 645 instrument 97 version, 645 instrument 07 version, as well as sorts of non-standard RS485 protocols. The uploaded data format can be configured via the host, and the JSON upload protocol can be MQTT protocol, HTTP POST protocol, HTTP GET protocol, and so on.


Multi Hosts Roll-Polling Support

Different network Devices Will be Identified and Responsed Respectively.

No More Crosstalk Issue While Communicating with Multi-Network Devices



User-Defined Heartbeat / Registration Packet

Easy for Cloud Communication and Device Identification



NTP Protocol Support

Getting Network Time Info for Serial Output or Data Upload



Multi Configuration Methods

Supports Web Browser Configuration, Obtaining Dynamic IP Via DHCP,
DNS Protocol Connected Domain Server Address



Multiple Protection, Safe and Stable


Onboard power supply and signal isolation can provide stable isolation voltage with high reliability and strong anti-interference. Built-in TVS (transient voltage suppression tube) can effectively suppress the surge voltage and transient peak voltage in the circuit, lightning proof & ESD protection. Built-in resettable fuse and protection diode to ensure stable output of current and voltage, prevents over-current and over-voltage proof, improves shockproof performance.



Aluminium Alloy Enclosure

Aluminium Alloy Enclosure With Sand Blasting And Anodic Oxidation
Solid And Durable, Fashion And Good Hand Feeling



Interface Available




Support Batch Customization

Support Software And Hardware Customization
Including Hardware Interface, LOGO, Label, Case Web Page, Etc.



Warranty Period: 12 months




  • Product Type: Serial server, Modbus Gateway, MQTT Gateway
  • Basic Function: Bi-directional transparent data transmission between RS485 and Ethernet
  • Communication Interface: 
    • RS485 port × 4
    • Ethernet port × 1
  • Power Supply Input: DC 6 ~ 45V screw terminal
  • Isolation Protection: 
    • Power Isolation
    • Signal Isolation
  • Ethernet: 
    • RJ45
    • 10 / 100M auto-negotiation RJ45 connector, 2 KV surge protection
  • Serial Port: Isolated RS485 (the 4 channels can receive and transmit independently at the same time)
  • Baud Rate: 300 ~ 115200 bps
  • Parity Bit: None, odd, even, mark, space
  • Data Bit: 5 ~ 9 bits
  • Flow Control: N/A
  • Configuration: Host, web browser, device management functions library
  • Communication Method: TCP/IP direct communication, VCOM
  • Operating Mode:  TCP server, TCP client (coexisting with TCP server), UDP, UDP multicast
  • Operating Temperature: -40℃ ~ 85℃
  • Humidity Range: 5% ~ 95% relative humidity
  • Dimension: 91.0 × 64.5 × 24.2 mm


Packing List
  • 1 x 4-Channel RS485 to Ethernet Module
  • 1 x Mini Flat Screwdriver
  • 1 x Mounting
  • 5 x Screws for mounting


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Tags: modbus, RTU, rs485, channel, input, output, isolated, ethernet, rj45, lan, mqtt, json, server, rs485 to ethernet, rs485 to rj45