// 3. Publish Data (Every 100ms for example) // Assuming you have a timer or cyclic task set to 100ms IF bConnected THEN // Construct a simple JSON payload (String format) // In real apps, use a JSON Serialize library for robustness PublishPayload := CONCAT('"pos":', REAL_TO_STRING(rPosition)); PublishPayload := CONCAT(PublishPayload, '');

If you are new to the ROS2 side of the equation, the core communication revolves around —anonymous channels where nodes publish or subscribe to data:

ROS2 relies on DDS as its underlying communication middleware. Some modern PLC platforms and runtime extensions allow CODESYS to interact directly with DDS data spaces. By defining matching Data Writers and Data Readers inside CODESYS, the PLC can publish and subscribe directly to ROS2 topics without intermediate translation. 2. The OPC UA Bridge

From those sleepless corrections came a framework stronger than a patched bridge. They codified authority: CODESYS would always own safety-critical states and determinism; ROS 2 would own perception, planning, and high-level coordination. They designed QoS rules, hardened the translator with schema checks, and introduced layered fallbacks: if ROS 2 stopped speaking, CODESYS would continue safe, predictable behavior. New diagnostic channels allowed operators to trace ROS 2 topic flows from the PLC screen—no longer a mysterious black box, but a transparent conversation.

Historically, industrial automation and advanced software robotics existed in separate silos. PLCs excelled at rugged, predictable execution but lacked the capability to process complex 3D point clouds, execute dynamic path planning, or run machine learning models. Conversely, ROS 2 excelled at high-level robotics but lacked native, deterministic drivers for diverse industrial hardware protocols like EtherCAT, PROFINET, and EtherNet/IP.

For a decade, engineers dreamed of merging these worlds: let the PLC handle the hard real-time I/O and safety, while ROS 2 handles the complex perception, path planning, and high-level decision-making.

Ros2 ~repack~ — Codesys

// 3. Publish Data (Every 100ms for example) // Assuming you have a timer or cyclic task set to 100ms IF bConnected THEN // Construct a simple JSON payload (String format) // In real apps, use a JSON Serialize library for robustness PublishPayload := CONCAT('"pos":', REAL_TO_STRING(rPosition)); PublishPayload := CONCAT(PublishPayload, '');

If you are new to the ROS2 side of the equation, the core communication revolves around —anonymous channels where nodes publish or subscribe to data: codesys ros2

ROS2 relies on DDS as its underlying communication middleware. Some modern PLC platforms and runtime extensions allow CODESYS to interact directly with DDS data spaces. By defining matching Data Writers and Data Readers inside CODESYS, the PLC can publish and subscribe directly to ROS2 topics without intermediate translation. 2. The OPC UA Bridge By defining matching Data Writers and Data Readers

From those sleepless corrections came a framework stronger than a patched bridge. They codified authority: CODESYS would always own safety-critical states and determinism; ROS 2 would own perception, planning, and high-level coordination. They designed QoS rules, hardened the translator with schema checks, and introduced layered fallbacks: if ROS 2 stopped speaking, CODESYS would continue safe, predictable behavior. New diagnostic channels allowed operators to trace ROS 2 topic flows from the PLC screen—no longer a mysterious black box, but a transparent conversation. For a decade

Historically, industrial automation and advanced software robotics existed in separate silos. PLCs excelled at rugged, predictable execution but lacked the capability to process complex 3D point clouds, execute dynamic path planning, or run machine learning models. Conversely, ROS 2 excelled at high-level robotics but lacked native, deterministic drivers for diverse industrial hardware protocols like EtherCAT, PROFINET, and EtherNet/IP.

For a decade, engineers dreamed of merging these worlds: let the PLC handle the hard real-time I/O and safety, while ROS 2 handles the complex perception, path planning, and high-level decision-making.