Learn BECKHOFF-TWINCAT with Real Code Examples
Updated Nov 27, 2025
Explain
TwinCAT turns a PC into a deterministic real-time controller.
Supports PLC, motion, robotics, CNC, and safety in one platform.
Uses IEC 61131-3 languages like ST, LD, FBD, SFC, IL, and CFC.
Integrates directly with EtherCAT for high-speed fieldbus control.
Provides engineering, debugging, visualization, and commissioning tools.
Core Features
TwinCAT XAE engineering environment
TwinCAT XAR real-time runtime
PLC programming in IEC languages
Motion Control and NC PTP modules
Built-in OPC UA, MQTT, and ADS communication
Basic Concepts Overview
Tasks - real-time execution cycles
POUs - functions, FBs, and programs
Mappings - link variables to I/O
Routes - connect engineering PC to runtime
ADS - standardized communication interface
Project Structure
SYSTEM - tasks & scheduling
I/O - EtherCAT and device maps
PLC - code modules and POUs
VISU - optional HMI/SCADA
CONFIG - real-time parameters
Building Workflow
Create a TwinCAT project
Configure EtherCAT I/O
Write PLC logic
Map variables to physical or virtual I/O
Download, run, test, and debug
Difficulty Use Cases
Beginner: simple PLC logic
Intermediate: motion control single-axis
Advanced: coordinated multi-axis systems
Expert: robotics kinematics or CNC
Architect: PC-based complex automation platforms
Comparisons
TwinCAT vs Siemens TIA Portal: TwinCAT excels at EtherCAT/motion; TIA more PLC mainstream.
TwinCAT vs Codesys: TwinCAT has stronger motion & EtherCAT performance.
TwinCAT vs Rockwell Studio5000: PC-based openness vs PLC-based robustness.
TwinCAT vs Mitsubishi GX Works: TwinCAT more modular and high-performance.
TwinCAT vs Omron Sysmac: Sysmac integrated hardware; TwinCAT more flexible PC control.
Versioning Timeline
1996 - Initial release of TwinCAT
2003 - TwinCAT 2 major version
2010 - TwinCAT 3 announced
2014 - TwinCAT 3 widespread adoption
2017 - New motion/kinematics modules
2019 - Major OPC UA & IoT improvements
2021 - Advanced multi-core runtime
2023 - CNC & robotics expansion
2024 - EtherCAT G performance upgrades
2025 - Latest stability & real-time enhancements
Glossary
ADS - Automation Device Specification protocol
POU - Program Organization Unit
DC - EtherCAT Distributed Clocks
XAR - TwinCAT runtime environment
Task - Real-time PLC execution cycle