Modbus to Mqtt mode

The instruction

CWT 4G gateway as Modbus master read slave (such as sensor, meter) on RS485 and push data to server by MQTT in JSON format.

Video Tutorial

How to set gateway and test

1.Set slave register parameters

For example, 4G gateway connect a temperature humidity sensor on RS485
RS485 communication parameters: 9600,n,8,1
Slave ID=1

Below is Modbus register map of the sensor

In “RS485” page

Go to “Modbus” page

Set the register0 of gateway to read humidity, register 1 to read temperature.

2.Set MQTT parameters

In “MQTT parameter” page

In ”Modbus 2” page

Restart device after setup

3.Subscribe MQTT message by MQTT.fx