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Ladder Editor

Use the ladder editor for rung-based PLC logic that still compiles into the same truST project, runtime, and debug workflow as Structured Text.

What it gives you

  • rung-based visual authoring
  • deterministic companion ST output
  • the same runtime/debug path as the rest of truST

Five-step quickstart

  1. Open examples/ladder/simple-start-stop.ladder.json in VS Code.
  2. Let truST auto-open the custom editor or use Reopen Editor With....
  3. Add or inspect contacts/coils in the rung.
  4. Save the file and inspect the generated companion ST.
  5. Run the same project through build/validate/runtime as you would for ST.

Best for

  • start/stop and seal-in circuits
  • timer/counter-heavy control
  • teams that already maintain ladder in another PLC environment

When not to use Ladder

  • when the logic is mostly state-machine behavior
  • when the control flow is primarily step/transition sequencing
  • when a straight ST file is simpler than a visual graph

Common mistakes

  • treating the diagram as if it had a separate runtime
  • editing the generated companion ST directly and expecting the visual model to stay authoritative
  • using Ladder for a state machine that would be clearer as Statechart or SFC

Example folder

  • examples/ladder