PLCcheck

PLC Code Validator

Paste AWL/STL or SCL code and get instant syntax checks, common error detection, and code statistics.

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Paste your PLC code on the left to start validation.

This basic validator checks syntax and common patterns. For deep analysis including logic errors, safety issues, migration readiness, and full documentation — PLCcheck Pro analyzes your complete program with AI.

Deep Analysis with PLCcheck Pro

Frequently Asked Questions

What errors does this tool detect?
The validator checks for common syntactic and structural issues in AWL/STL and SCL code: missing block-end instructions (BE/BEA), unclosed parentheses, unknown commands, duplicate output assignments, timers without time values, undefined jump targets, missing semicolons, unclosed IF/FOR/WHILE blocks, and more. It does not perform semantic or runtime analysis.
Can it check Ladder Logic (KOP/LAD)?
No. This tool currently supports text-based PLC languages only: AWL/STL (Instruction List) and SCL/ST (Structured Text). Ladder Logic (KOP/LAD) and Function Block Diagram (FUP/FBD) require graphical editors and cannot be validated as text.
Is my code sent to a server?
No. All validation runs entirely in your browser using JavaScript. Your code never leaves your device — no data is uploaded, stored, or transmitted to any server.

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