Transitioning from CANopen to EtherCAT: Understanding CoE (CAN Application Protocol over EtherCAT)

What is CoE (CAN Application Protocol over EtherCAT)?

CoE (CAN Application Protocol over EtherCAT) is one of the key communication profiles supported by EtherCAT®. It allows users familiar with CANopen to leverage the same communication principles in EtherCAT networks, making it an ideal protocol for device manufacturers transitioning to EtherCAT.

Key Features of CoE:

  • CANopen Object Dictionary
  • Process Data Objects (PDOs) mapping
  • Emergency error messages & diagnostics
  • Service Data Objects (SDOs)

These features help streamline the configuration of EtherCAT SubDevices, ensuring compatibility and ease of use.

The Role of CoE in EtherCAT Communication

For developers and engineers already working with CANopen, CoE simplifies EtherCAT adoption by retaining familiar communication principles. EtherCAT networks using CoE maintain the flexibility of Process Data Object (PDO) mapping and can leverage standard diagnostics and error handling capabilities.

EtherCAT also supports several standardized profiles from CANopen, including CiA 402 for drives and motion control, which enables seamless integration of devices. Furthermore, the EtherCAT Technology Group (ETG) has defined how to map CiA 402 to EtherCAT through the ETG.6010 specification.

 

Benefits for Device Manufacturers

CoE offers significant advantages for device manufacturers moving from CANopen to EtherCAT:

  • Reduced Development Effort: Since CoE shares communication and data concepts with CANopen, manufacturers can reuse much of their existing software and expertise, minimizing the need for extensive, time-consuming code rewrites.
  • Simplified Testing: By maintaining familiar diagnostic and communication mechanisms, developers can reduce testing time, as much of the system behaves similarly to CANopen.
  • Standardized Profiles: With support for CANopen profiles like CiA 402, manufacturers can retain compatibility with existing systems while upgrading to EtherCAT’s faster and more efficient communication protocol.

 

Key Takeaways

By implementing CoE, developers can seamlessly transition from CANopen to EtherCAT without starting from scratch. This significantly reduces development and testing time while preserving compatibility with existing systems.