ControlForge Structured Text

Professional Structured Text (IEC 61131-3) development environment for PLC programming in Visual Studio Code.

Key Features

• Function Block IntelliSense: Auto-complete for FB outputs (myTimer.Q, upCounter.CV)
• Rich Syntax Highlighting: Complete IEC 61131-3 language support
• Smart Code Completion: Context-aware suggestions for keywords, types, and variables
• Code Validation: Built-in syntax validation and error detection
• Code Snippets: Pre-built templates for common PLC patterns

Screenshots

Syntax Highlighting & IntelliSense

Rich syntax highlighting for all IEC 61131-3 constructs

Getting Started

Installation

1. Open Visual Studio Code
2. Go to Extensions (Ctrl+Shift+X)
3. Search for "ControlForge Structured Text"
4. Click Install

Commands

• ControlForge Structured Text: Validate Syntax - Checks the current file for syntax errors
• ControlForge Structured Text: Check LSP Status - Verifies if the Language Server Protocol is running correctly
• ControlForge Structured Text: Show Index Statistics - Displays information about indexed workspace symbols

Quick Start

1. Create a new file with .st or .iecst extension
2. Start typing - syntax highlighting activates automatically
3. Use Ctrl+Space for IntelliSense completion
4. Type function block instances followed by . for member completion

Function Block Completion Example

PROGRAM MyProgram
VAR
    startTimer : TON;          // Timer On-Delay
    partCounter : CTU;         // Counter Up
    emergencyStop : R_TRIG;    // Rising Edge Trigger
END_VAR

// IntelliSense in action:
startTimer.     // Shows: Q (BOOL), ET (TIME)
partCounter.    // Shows: Q (BOOL), CV (INT)
emergencyStop.  // Shows: Q (BOOL)
END_PROGRAM

Language Features

Smart IntelliSense

• Function Block Members: Auto-complete for all standard IEC 61131-3 function blocks
  • Timers: TON, TOF, TP → Q, ET
  • Counters: CTU, CTD, CTUD → Q, CV, QU, QD
  • Edge Detectors: R_TRIG, F_TRIG → Q
  • Bistables: RS, SR → Q1
• Keyword Completion: All IEC 61131-3 keywords and constructs
• Data Type Suggestions: BOOL, INT, REAL, TIME, STRING, etc.
• Variable Detection: Automatically detects declared variables
• Code Snippets: Templates for common patterns (IF-THEN, FOR loops, etc.)

Syntax Highlighting

• Keywords: IF, THEN, ELSE, FOR, WHILE, CASE, VAR, END_VAR
• Data Types: BOOL, INT, REAL, TIME, STRING, ARRAY, STRUCT
• Operators: AND, OR, NOT, XOR, :=, +, -, *, /
• Comments: // single-line and (* *) multi-line
• Literals: String, numeric (decimal, hex, binary), time literals
• Function Blocks: Standard IEC 61131-3 function blocks

Editor Features

• Auto-closing: Brackets, quotes, and parentheses
• Comment Toggle: Ctrl+/ for quick commenting
• Word Matching: Intelligent word selection and highlighting
• File Association: Automatic recognition of .st and .iecst files

Supported File Extensions

• .st - Standard Structured Text files
• .iecst - IEC 61131-3 Structured Text files

Requirements

• Visual Studio Code 1.100.0 or higher
• Operating System: Windows, macOS, or Linux

Commands

Access these commands via the Command Palette (Ctrl+Shift+P):

• "Structured Text: Validate Syntax" - Check code for syntax errors

What's New in v1.2.2

• Fixed LSP Initialization Issues: Resolved critical bug with vscode-languageclient module
• Enhanced Error Handling: Added robust error handling for language server activation
• LSP Status Command: Added command to verify Language Server Protocol is running

What's New in v1.2.0

• Go to Definition & Find References: Navigate through Structured Text code
• Member Access Navigation: Navigate from instance members to their definitions
• Language Server Protocol (LSP): Full integration for advanced IDE features
• Cross-file Navigation: Navigate between files with symbol references
• IEC 61131-3 Definition Files: Standard function block definitions included for hover, navigation and completion

What's New in v1.1.0

• Function Block Member Completion: Auto-complete for function block outputs
• Enhanced Parser: Better variable and FB instance detection
• Comprehensive Testing: Automated tests ensure reliability
• Improved Documentation: Better examples and guides

Support & Feedback

• Website: controlforge.dev
• Issues: GitHub Issues
• Discussions: GitHub Discussions
• Rate & Review: VS Code Marketplace

License

Licensed under the Business Source License 1.1 (BUSL-1.1).
For details, see License Terms.

Made for the PLC programming community