EtherCAT Technology Group (ETG)

Complementary technologies:
EtherCAT and OPC UA for Industrie 4.0 and IoT


Industrie 4.0 and IoT demand seamless and continuous communication through all layers and levels within the digital factory, as well as externally through cloud-based services and other Internet technologies. The ETG and the OPC Foundation seek to achieve these requirements with the common definition of open interfaces between both of their technologies.

The EtherCAT Technology Group (ETG) and the OPC Foundation agree that their technologies complement each other perfectly: EtherCAT as the real-time-capable Ethernet fieldbus for machine and plant controls, leveraging the EtherCAT Automation Protocol (EAP) for lean data exchange between masters. OPC UA as a platform for scalable communication with integrated Security by Design, enabling encrypted data transfer up to MES/ERP systems and into the cloud.

A well-defined management shell transforms existing devices and machine units with EtherCAT communication for cyclic and deterministic process data exchange into an i4.0 conform communication.

The shell includes the virtual representation of the device data and the technical functionality. The i4.0 component captures communication relations inside the shell and allows a consistent engineering. Security measures protect the enclosed environment inside the component from unauthorized manipulation.


Technical content

Content of the joint specification:

  • Definition of an interface between EtherCAT and OPC UA that allows the implementation of a management shell for a i4.0 conform component.
  • Use cases define the requirements for the interface specification.
  • The EtherCAT information sets, represented by an object dictionary model, are mapped to the OPC UA information model. This allows access to the EtherCAT data model with basic OPC UA services.
  • A generic approach for the mapping of an EtherCAT object dictionary to the OPC UA information model unifies the data structure. Internal information of the component becomes accessible via OPC UA.
  • The extension of OPC UA with a Publish/Subscriber communication model provides new services for cyclic publishing of data to one or many subscriber devices on the i4.0 communication layer – the EAP protocol is well suited to be the underlying communication layer for the OPC UA Pub/Sub services

This provides access to the information set of the component with the benefits of an OPC UA communication, like security and authentication.

  • Secured and authenticated access
  • Monitoring of communication relations
  • Access of publically available information and process data
  • Setup and configuration of communication relations
  • Configuration data of EtherCAT devices


More Information

See here: Video “OPC UA and EtherCAT” by Martin Rostan, Executive Director ETG

Both organizations, OPC Foundation and EtherCAT Technology Group agreed, in the frame of a Memorandum of Understanding (MoU), to develop these interfaces in close cooperation, rather than focusing on their own technology extensions into the core area of the other.

About EtherCAT Technology Group

The EtherCAT Technology Group (ETG) is an association in which key user companies from various industries and leading automation suppliers join forces to support, promote and advance the EtherCAT technology. With over 3400 members from 58 countries the EtherCAT Technology Group has become the largest fieldbus organization in the world. Founded in November 2003, it is also the fastest growing association of its kind. EtherCAT is the fastest Industrial Ethernet technology and stands for high-performance, low-cost, ease of use and a flexible topology. It was introduced in 2003 and became an international standard and a SEMI standard in 2007. The EtherCAT Technology Group promotes EtherCAT and is responsible for its continued development. EtherCAT is also an open technology: anyone is allowed to implement or use it.

EtherCAT Technology Group
Ostendstrasse 196
90482 Nuremberg, Germany