CODESYS And TwinCAT

This is the day-to-day authoring path for the most important vendor-family surface in truST.

Use this page for

• vendor_profile = "codesys"
• vendor_profile = "twincat"
• authoring style and formatting expectations
• PLCopen/CODESYS interchange
• TwinCAT-adjacent authoring expectations
• library stub strategy

What truST is good at here

• authoring ST in a CODESYS/TwinCAT-adjacent style
• formatting and diagnostics under the vendor profile
• PLCopen interchange and migration workflows
• keeping editor productivity when vendor-specific libraries are not fully implemented yet

Day-to-day workflow

1. Set vendor_profile in trust-lsp.toml.
2. Keep application code in normal src/ folders.
3. Add [[libraries]] stub folders for vendor-only symbols you still need for completion, hover, and navigation.
4. Use PLCopen import/export when moving source in or out of vendor tooling.

Library stub pattern

If you need symbols from vendor libraries that truST does not ship, use the stub pattern shown in examples/vendor_library_stubs:

• declare the symbols locally in ST
• wire the folder through [[libraries]]
• keep expectations clear: symbol/type contracts, not vendor runtime semantics

Best starting points

• PLCopen interoperability
• Vendor libraries
• Vendor profile reference
• examples/vendor_library_stubs

Limits

truST is strongest on authoring and interchange, not on reproducing every vendor project package behavior.