CODESYS And TwinCAT

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

Fits

• 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

For 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.