CANopen is a robust communication protocol designed to streamline industrial automation, ensuring seamless data exchange between various devices. Since its inception, it has revolutionized how industries manage machine-to-machine communication, providing reliability, efficiency, and interoperability.
What is CANopen?
Table of Contents
CANopen is an open, flexible, and highly configurable communication protocol based on the CAN (Controller Area Network) standard. Initially developed for industrial automation, its applications now span various fields, including medical devices, maritime technology, and robotics.
Key Features:
- High-speed and reliable communication
- Supports real-time data transfer
- Scalable network architecture
- Standardized profiles for different applications
How Does CANopen Work?
CANopen operates on a hierarchical structure, utilizing multiple communication objects for data exchange. Devices within a CANopen network communicate using:
- Process Data Objects (PDOs) – Real-time data exchange
- Service Data Objects (SDOs) – Device configuration and parameter updates
- Network Management (NMT) Protocol – Controls and monitors network status
- Synchronization (SYNC) & Emergency Messages (EMCY) – Ensures time-critical processes
Key Benefits of CANopen
- Interoperability – Ensures seamless communication between different manufacturers’ devices.
- Flexibility – Suitable for small and large-scale networks.
- Cost-Efficiency – Reduces wiring complexity and maintenance costs.
- Reliability – Built-in error detection mechanisms enhance network stability.
CANopen vs. Other Protocols
| Protocol | Speed | Scalability | Cost | Best Use Cases |
| CANopen | Medium | High | Low | Industrial automation, robotics |
| Modbus | Low | Medium | Low | Simple automation systems |
| PROFINET | High | High | High | High-performance industrial networks |
| Ethernet/IP | Very High | High | Medium | IoT, factory automation |
CANopen Network Architecture
CANopen follows a master/slave configuration but can also operate in a decentralized manner. It supports:
- Linear, star, and tree topologies
- Up to 127 nodes per network
- Data rates ranging from 10 kbps to 1 Mbps
CANopen Data Transmission
Data transfer in CANopen occurs through different communication objects:
- PDOs – High-speed real-time data exchange
- SDOs – Configuration data transfer
- NMT Messages – Manages network states
- SYNC & EMCY Messages – Synchronization and error detection
CANopen Devices & Components
A CANopen system comprises:
- Controllers – PLCs and industrial PCs
- Sensors – Pressure, temperature, and motion sensors
- Actuators – Motors, relays, and valves
- Cables & Connectors – Standardized physical connections
Setting Up a CANopen System
- Define Network Topology
- Assign Node IDs
- Configure PDO Mapping
- Implement Network Management (NMT)
- Test and Validate Communication
Common Applications of CANopen
- Industrial Automation – Factory machinery, conveyors, and robotics
- Medical Devices – Imaging systems, patient monitoring devices
- Automotive Systems – Engine control, braking systems
FAQs
CANopen is widely used in industrial automation, automotive systems, medical devices, and maritime applications.
CANopen supports data rates from 10 kbps to 1 Mbps, depending on network configuration and cable length.
CANopen offers higher speed, better real-time capabilities, and standardized device profiles compared to Modbus.
Yes, emerging technologies are integrating CANopen with wireless communication protocols for increased flexibility.
A CANopen network can support up to 127 nodes.
CANopen adds higher-layer protocols, standardized device profiles, and network management features to the basic CAN framework.
Conclusion
CANopen remains a vital communication protocol in industrial automation, providing a cost-effective, reliable, and scalable solution for machine-to-machine communication. With continuous advancements, it will play an even greater role in future automation systems.