Modbus TCP

Bridging the Gap: Connecting a Turck TBEN-S1-8DXP to a Dobot MG400 via Modbus TCP

ByGašper

In my latest video, I tackled an integration that many collaborative robot users are curious about—connecting a Turck TBEN-S1-8DXP digital I/O module to a Dobot MG400 desktop cobot using Modbus TCP.

And here’s the best part: I programmed the entire interaction using Dobot’s Blockly graphical programming language — no complex text-based coding required.

Why does this matter? The MG400 is lightweight yet powerful, but adding a rugged, decentralized I/O block like the Turck TBEN-S1-8DXP unlocks a world of flexibility. You get 8 digital inputs and/or 8 outputs in an IP67-rated housing — perfect for sensors, actuators, and tool changers right next to your robot.

The highlights from the build:

  • Modbus TCP setup – The TBEN-S1-8DXP supports Modbus TCP natively. I configured the module’s IP address and set up the MG400 as the Modbus client over standard Ethernet.
  • Blockly programming – Using Dobot’s drag-and-drop Blockly interface, I built the Modbus communication logic visually. Blocks for reading holding registers, writing coils, and looping conditions made the integration surprisingly fast and intuitive.
  • Register mapping – I walked through which Blockly blocks map to specific Turck input/output addresses, making it easy to replicate the setup.
  • Real-world testing – From turning on a pickup light to reading a part-present sensor, the Blockly-coded Modbus TCP connection delivered reliable, low-latency control without a single line of traditional code.

If you’re automating a small bench or a lab cell and want to expand the MG400’s I/O without a PLC — or deep coding skills — this Modbus TCP + Blockly pairing is a smart, accessible move.

👉 Watch the video to see the step-by-step IP configuration, Blockly logic building, and a live demo of the MG400 controlling the Turck I/O module.