adstec/irf-modbus-gw repository overview

⁠Modbus RTU to Modbus TCP Converter for ADS-TEC IRF3000

Sample container by ADS-TEC Industrial IT: the open-source gateway mbusd⁠ in the rootless Docker of the IRF3000 industrial firewalls. Modbus TCP clients (SCADA, HMI, PLC) connect to the IRF on TCP port 502; the gateway forwards the requests to the Modbus RTU slaves on the integrated RS-485 interface.

• The unit identifier of the Modbus TCP request selects the RTU slave
• Several clients at the same time, requests are serialized on the bus
• RS-485 direction switching is handled by the container
• Exception 0x0B (Gateway Target Device Failed to Respond) if a slave does not answer

⁠Quick start

Enable Access to RS485 under "Configuration > Services > Docker" on the IRF, then:

docker run -d --name modbus-gw --restart unless-stopped \
  --network host --device /dev/ttyS1 \
  -e SERIAL_SPEED=19200 -e SERIAL_MODE=8E1 \
  adstec/irf-modbus-gw

Modbus TCP has no authentication. Restrict the IRF forwarding rule for port 502 to the network of your SCADA/HMI systems and never forward it from a WAN interface. Setup and port forwarding are described in the Docker Application Note of ADS-TEC Industrial IT.

⁠Links

• Source files on GitHub⁠ - Dockerfile, IRF setup script and README
• IRF3000 industrial firewall⁠ - product page of ADS-TEC Industrial IT

⁠Platforms and license

linux/arm64 (IRF3000), linux/arm/v7. mbusd is licensed under the BSD 3-Clause license.