Glossary Updates12 new terms added to the glossaries · October 2, 2026, 22:44 CEST
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Glossary · Industrial communication

CANopen over EtherCAT (CoE)

Also known as: CoE

German: CANopen over EtherCAT (CoE)

In EtherCAT, CANopen over EtherCAT (CoE) is the mailbox protocol that carries the CANopen application layer, with its object dictionary, SDO parameter access, PDO mapping and device profiles such as CiA 402 for drives, over EtherCAT.

  • Industrial communication
  • Standards

In one sentence

CoE carries the CANopen application layer over EtherCAT: object dictionary, SDO parameter access, PDO mapping and profiles such as CiA 402.

Example

A case packer's controller writes the acceleration limits of its servo drives through CoE SDOs in Pre-Operational, then exchanges target positions and status words cyclically as mapped PDOs.

How it applies

  • Engineering: CoE lets vendors reuse CANopen device profiles and tools. Parameters are addressed by object index and subindex; the process data objects that are mapped go into the cyclic EtherCAT frame.
  • Commissioning: SDO access works from Pre-Operational onward (see EtherCAT state machine). Startup parameters that the main device writes on every start override values set by hand in the device.
  • Integration: CoE is one of several EtherCAT mailbox protocols, next to File access (FoE), Ethernet (EoE) and the Servo drive profile over EtherCAT (SoE). A device lists the ones it supports in its EtherCAT Slave Information (ESI).
  • Documentation: The documentation team provides the object dictionary with indices, data types, units, access rights and defaults, and marks which objects can be mapped as PDOs.

CoE vs. CANopen

CANopen runs on the CAN bus; CoE keeps its application layer and replaces CAN with EtherCAT. The object model stays, but CAN-specific functions such as node IDs for message priority don't apply.

By knowledge.aitechdoc.world · Published September 28, 2026 · Last reviewed

Source: IEC 61158 (Type 12) and IEC 61784-2 (communication profile family 12), CiA 301, and EtherCAT Technology Group publications

Definitions follow the cited standards and specifications. Where a source is a copyrighted publication, such as an ISO, IEC or EN standard, the definition is a close paraphrase, not a verbatim quotation, so as not to infringe copyright. We recommend reading the original publication. The sections “How it applies” are editorial commentary by AI TechDoc Blog and are not part of any standard.

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