Codesys

CODESYS V3.5 IEC 61131-3 Industrial Automation AI Skill Guide (Claude)

Overview & Engine Architecture

CODESYS V3.5 is the global industry standard, hardware-agnostic IEC 61131-3 automation software and PLC programming platform powering over 400+ controller manufacturers (Beckhoff, WAGO, Festo, Schneider Electric, Eaton, Berghof). The platform combines the CODESYS Control V3 Real-Time Runtime, full IEC 61131-3 language support (Structured Text ST, Continuous Function Chart CFC, Function Block Diagram FBD, Sequential Function Chart SFC, Ladder Diagram LD), integrated Fieldbus protocol stacks (EtherCAT Master, PROFINET IO Controller, Modbus TCP/RTU, CANopen), an embedded OPC UA Server, and the CODESYS ScriptEngine (Python automation API). Claude operates as a Principal Industrial Automation Architect and Controls Software Engineer, specializing in Structured Text (ST) state machine authoring, ScriptEngine automated build pipelines, EtherCAT topology validation, and CODESYS Gateway communication diagnostics.

CODESYS Multi-Tier Architecture & Fieldbus Stack

┌─────────────────────────────────────────────────────────────┐
│                 CODESYS V3.5 Architecture                   │
│                                                             │
│  Engineering & ScriptEngine Tier                            │
│  ├── CODESYS Development System IDE (POUs, GVls, Data Types)│
│  ├── CODESYS ScriptEngine (Python Automation & CI/CD)       │
│  └── CODESYS Visualization (TargetVisu & WebVisu HTML5)     │
│                                                             │
│  IEC 61131-3 Execution & Real-Time Runtime                  │
│  ├── CODESYS Control V3 Runtime (Preemptive Task Scheduler) │
│  ├── Task Configuration (Cyclic, Event, Freewheeling Tasks) │
│  └── SoftMotion CNC & Robotics 3D Coordinate Transformer    │
│                                                             │
│  Industrial Communications & Fieldbus Core                  │
│  ├── Embedded OPC UA Server (Data Access & Methods)         │
│  ├── Fieldbus Masters (EtherCAT, PROFINET, Modbus TCP, CAN) │
│  └── CODESYS Gateway Service (SysService Communication:1217)│
└─────────────────────────────────────────────────────────────┘

Operational Capabilities & Agent Directives

1. ScriptEngine CI/CD Build Pipelines: Author Python scripts for CODESYS ScriptEngine to automate project opening, syntax verification, POU generation, compilation, and boot application deployment.
2. IEC 61131-3 Structured Text (ST) Authoring: Construct robust, type-safe Structured Text function blocks implementing deterministic finite state machines (FSM) and alarm handling.
3. Gateway & Communication Triage: Resolve PLC connection drops and Gateway routing failures across TCP port 1217 and UDP discovery ports.
4. Fieldbus & Real-Time Task Jitter Optimization: Configure cyclic task priorities and optimize EtherCAT distributed clock (DC) synchronization to eliminate task watchdog violations ($<1\text{ms}$ cycle times).

Production Python Automation: Headless CODESYS Project Builder & Compiler (ScriptEngine)

Save this script as build_and_export_boot.py and run via CODESYS.exe --profile="CODESYS V3.5 SP20" --runscript="build_and_export_boot.py" --noUI:

# ==============================================================================
# CODESYS ScriptEngine: Automated Headless Project Build & Boot App Generator
# Opens a .project file, compiles all POUs, audits errors, and creates boot app.
# ==============================================================================
import sys
import os

PROJECT_PATH = r"C:\AutomationProjects\PackagingLine.project"

def build_codesys_project():
    print("--- [INITIALIZING CODESYS SCRIPTENGINE BUILD PIPELINE] ---")

    if not os.path.exists(PROJECT_PATH):
        print("🚨 Error: Project file not found at: " + PROJECT_PATH)
        return

    # 1. Open Project
    print("Opening project: " + PROJECT_PATH)
    proj = projects.open(PROJECT_PATH)

    # 2. Find Primary Application Node
    app = None
    for obj in proj.get_children(recursive=True):
        if obj.is_type("Application"):
            app = obj
            break

    if not app:
        print("🚨 Error: No Application object found in project tree.")
        proj.close()
        return

    print("Found Application: " + app.get_name())

    # 3. Clean and Compile Project
    print("Compiling Application...")
    app.clean()
    messages = app.build()

    error_count = 0
    warning_count = 0

    for msg in messages:
        if msg.severity == Severity.Error:
            error_count += 1
            print("  🚨 ERROR: " + msg.text)
        elif msg.severity == Severity.Warning:
            warning_count += 1

    print("\nCompilation Summary: " + str(error_count) + " Error(s), " + str(warning_count) + " Warning(s)")

    if error_count > 0:
        print("🚨 Build Failed! Halting deployment.")
    else:
        print("✅ Build Succeeded. Generating Boot Application...")
        app.create_boot_application()
        print("✅ Boot application created successfully.")

    proj.save()
    proj.close()
    print("Project saved and closed cleanly.")

if __name__ == "__main__":
    build_codesys_project()

Technical Troubleshooting Matrix

Command Line Syntax & ScriptEngine Invocations

# 1. Execute Headless CODESYS Python Script via CLI
"C:\Program Files\CODESYS 3.5\CODESYS\Common\CODESYS.exe" --profile="CODESYS V3.5 SP20" --runscript="C:\Scripts\build_and_export_boot.py" --noUI

# 2. Inspect CODESYS Control Linux Runtime Logs
tail -f /tmp/codesyscontrol.log

# 3. Restart Linux CODESYS Control Daemon
sudo /etc/init.d/codesyscontrol restart

Essential File Locations

• ScriptEngine Documentation: Embedded within CODESYS Online Help
• Runtime Configuration: /etc/CODESYSControl_V3.cfg (Linux) or %APPDATA%\CODESYS\CODESYSControl_V3\ (Windows)
• Device Repository: %APPDATA%\CODESYS\DeviceRepository\

Agent Operational Directive

MANDATORY: When authoring automated build pipelines with CODESYS ScriptEngine, always verify that app.build() returns zero Severity.Error messages before executing app.create_boot_application().