Attention

IronPLC supports IEC 61131-3 Structured Text excluding I/O mapping.

Troubleshooting

This guide helps you resolve common issues with the IronPLC extension.

No Syntax Highlighting

Symptom: Files appear as plain text without colors.

Solutions:

1. Check file extension: Ensure your file has a supported extension. See Overview for the full list of supported languages and extensions.

2. Check language mode: Look at the bottom-right corner of the window. It should show “IEC 61131-3”, “Structured Text”, “TwinCAT POU”, or “PLCopen XML”. Click it to change the language mode if needed.

3. Reload the window: Run “Developer: Reload Window” from the Command Palette.

No Diagnostics Appearing

Symptom: The extension does not show any errors or warnings, even for invalid code.

Solutions:

1. Check the compiler is running: Look at the Output panel (View ‣ Output) and select “IronPLC” from the dropdown. You should see startup messages.

2. Check for E0001: If the compiler was not found, diagnostics will not work. See E0001.

3. Enable debug logging: Set ironplc.logLevel to DEBUG and check the Output panel for error messages.

Extension Not Activating

Symptom: The extension appears installed but nothing happens when opening ST files.

Solutions:

1. Check extension status: Open the Extensions view and find IronPLC. Ensure it shows as enabled, not disabled.

2. Check for conflicts: Disable other IEC 61131-3 or PLC extensions that might conflict.

3. View extension logs: Open Help ‣ Toggle Developer Tools, go to the Console tab, and look for messages containing “ironplc”.

4. Reinstall the extension: Uninstall the extension, reload the window, then reinstall it.

Collecting Debug Information

When reporting issues, please collect the following information:

1. Version information:

   • Development environment and version (Help ‣ About)

   • IronPLC extension version (Extensions view)

   • Compiler version (run ironplcc --version)

   • Operating system and version

2. Enable detailed logging:

   {
     "ironplc.logLevel": "TRACE",
     "ironplc.logFile": "/tmp/ironplc-debug.log"
   }
   

3. Reproduce the issue with logging enabled.

4. Collect logs:

   • The log file specified above

   • Output panel content (View ‣ Output ‣ IronPLC)

   • Developer Tools console (Help ‣ Toggle Developer Tools)

5. Create an issue on GitHub with:

   • Steps to reproduce the problem

   • Expected vs. actual behavior

   • Version information

   • Relevant log excerpts

Performance Issues

Symptom: The editor is slow or unresponsive when editing ST files.

Solutions:

1. Check file size: Very large files may cause slowdowns. Consider splitting large programs into multiple files.

2. Reduce log level: If you have verbose logging enabled, set ironplc.logLevel back to ERROR.

3. Disable file logging: Remove any ironplc.logFile setting.

4. Check for loops: The compiler may take longer on code with complex nested structures. Simplify where possible.

Resetting the Extension

If all else fails, try a clean reset:

1. Uninstall the IronPLC extension

2. Delete the extension’s global storage:

   • Windows: %USERPROFILE%\.vscode\extensions\ironplc.* (or %USERPROFILE%\.cursor\extensions\ironplc.* for Cursor)

   • macOS/Linux: ~/.vscode/extensions/ironplc.* (or ~/.cursor/extensions/ironplc.* for Cursor)

3. Reload the development environment

4. Reinstall the extension from the marketplace