Serial to Ethernet / WiFi - Modbus to MQTT Gateway


  • Modbus RTU to MQTT
  • 802.11b/g/n WiFi and 10/100Mbps Ethernet with 2 IPs
  • Supports up to 32 Topics, register length adjustable
  • Supports queries 4 remote TCP devices
  • Simple MQTT settings by web browser configuration
  • Easy installation with Windows IP utility
  • On line F/W upgrade
  • Watch Dog Function


The MQTT Wi-Fi / Ethernet / Serial Gateway, GW211W-MQ provides an easy to deploy device to send RS-232/RS-485 Serial Modbus RTU Data communications to MQTT TCP networks on hard-wired Ethernet or over wireless WiFi networks.  The MQTT Gateway works with standard Modbus Slave device, such as PLCs, IoT Sensors, Energy meters (AMRs), Solar Inverters, Wind Turbines, IO Modules, Flow Meters and more. The MQTT Gateway is built for use in light industrial environments and features a compact wall-mount design. It operates from 9-32VDC power supply voltages with both DC Jack and terminal block connectors and is easy to configure through its web GUI interface.

Technical Notes

Modbus Notes

Modbus TCP / RTU integration

Since its inception in 1979 Modbus has become a widely used communication protocol in the field of industrial automation. Originally based on serial interfaces (RS232 and RS485) Modbus RTU enjoys widespread use throughout many different industries. Since then Ethernet has become the network of choice and many industrial devices now have native Ethernet interfaces.

Ordering Information

Order Code Description
CT-GW211W-MQ Serial to Ethernet / WiFi - Modbus to MQTT Gateway
DRK04 Din Rail Kit for CT-GW211-MQ

More Information