Wittelb WIN-GW-4G+IO (4DDAM)+ETH RS485 to 4G MQTT Ethernet IoT Gateway

Access the gateway's web UI via its Ethernet or cellular IP address. Navigate to the 'Modbus Mapping' or 'Serial Server' section. Here, define the RS485 port parameters (baud rate, data bits, parity, stop bits) and map each Modbus RTU slave device's register addresses to a corresponding Modbus TCP unit ID and IP port. The gateway will then listen for TCP connections and translate requests to the serial bus. Typical setup involves setting a static TCP port (e.g., 502) and defining the serial baud rate to match your slave devices, commonly 9600 or 19200 bps.

In the web UI, go to the 'Cloud Services' or 'MQTT' configuration page. Enter your broker details (server address, port, username, password). Then, in the 'Data Points' or 'Topics' section, link specific Modbus register addresses or analog input channels to MQTT topics. You can set the publishing interval (e.g., every 30 seconds). The gateway will read the specified data, format it into a JSON or plain text payload, and publish it to the configured topic. Ensure your firewall allows outbound traffic to the MQTT broker's port, usually 1883 for unencrypted or 8883 for TLS.

The gateway requires a stable DC power source between 15 and 40 volts, such as a 24VDC industrial power supply. Connect the positive wire to the terminal marked 'V+' or 'Power In+' and the negative wire to 'GND' or 'Power In-'. Use appropriately sized wire for the expected current draw. For remote installations, consider adding surge protection on the power line. The wide input range allows compatibility with solar-charged battery systems (12V/24V) and standard industrial power rails. Always ensure the power source is adequately rated and fused according to local electrical codes for safety.