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

Glossary · Industrial communication

CANopen

Also known as: CiA 301

German: CANopen

In industrial communication, CANopen is a higher-layer protocol and device profile family for the CAN bus, maintained by CAN in Automation (CiA). Each device has an object dictionary; process data are exchanged in PDOs and configuration data in SDOs.

  • Industrial communication
  • Standards

In one sentence

CANopen is a CAN-based higher-layer protocol with object dictionary, PDOs and SDOs and standardized device profiles (CiA 301, EN 50325-4).

Example

A servo drive with a CANopen interface follows the CiA 402 drive profile, so the controller can command position mode with standard objects.

How it applies

  • Engineering: The object dictionary describes all parameters and data of a device; an electronic data sheet (EDS file) makes it available to configuration tools. Device profiles such as CiA 402 for drives let devices from different manufacturers behave alike.
  • Commissioning: Node IDs and bit rates are set on each device. The network management (NMT) master switches the nodes to the operational state, and PDO mapping defines which objects are sent cyclically.
  • Operation: Heartbeat or node guarding detects failed nodes; emergency messages (EMCY) report device errors.
  • Documentation: The documentation team publishes the object dictionary with index, subindex, data type, access rights and units, and states which profile the device implements. This is the reference integrators actually need.

CANopen vs. EtherCAT

EtherCAT can carry the CANopen application layer (CoE, CANopen over EtherCAT), so object dictionaries and drive profiles are reused on Ethernet hardware. The transport and the timing behavior are different, though.

The Information model idea is similar: CANopen's object dictionary is a structured description of what a device offers, which makes it a useful source for semantic documentation.

By knowledge.aitechdoc.world · Published September 26, 2026 · Last reviewed

Source: EN 50325-4, Industrial communications subsystem based on ISO 11898 (CAN) for controller-device interfaces — Part 4: CANopen

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.

Seen a mistake? Send us a note!