IEC 61131-3 Language Editors

KVPAC IDE implements the four most-used IEC 61131-3 programming languages in one web-based editor. Switch between languages per program organisation unit (POU) without leaving the project.

Choose a Language Editor

Editor Type Typical Use
LD — Ladder Diagram Graphical Relay logic, interlocks, machine control
ST — Structured Text Textual Algorithms, data processing, complex calculations
FBD — Function Block Diagram Graphical Signal flow, continuous control, reusable blocks
SFC — Sequential Function Chart Graphical Sequences, batch processes, state machines

What the Editors Share

  • One project, mixed languages — each POU uses the language that fits the task
  • Live syntax checking — errors surface while you type, before compile
  • AI/MCP assistance — generate, explain, and refactor code in every language
  • Browser-based — no installation; runs in Chrome, Edge, and Firefox
  • Simulation ready — test any language editor output without hardware

Cross-Language Consistency

Variables, data types, and function blocks are shared across all four editors. A function block written in ST is called from an LD rung or an FBD sheet without conversion work.


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