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OpenCDD

The IEC Common Data Dictionary (IEC CDD) is a structured, versioned, multilingual catalogue of product characteristics — what kinds of electrotechnical products exist, what properties describe them, and how those properties relate to each other. It is maintained by IEC Technical Committee 3 (Information structures, documentation and graphical symbols) and published under IEC 61360.

The single-line summary, paraphrased from IEC 61360-1:2017 (Edition 4.0), is that the dictionary captures the concept of a product with entities called “classes” and the characteristics of that product with entities called “properties”. A class represents a kind of thing (e.g. “capacitor”, “fixed capacitor”); a property represents a measurable or descriptive trait of that kind (e.g. “capacitance”, “rated voltage”). Classes are arranged in a single-inheritance classification tree, and every property a class declares is inherited by its subclasses.

Why it exists

Component suppliers, manufacturers, e-commerce platforms, engineering tools, and regulators all need to describe the same kinds of products. Without a shared dictionary, every party invents its own identifiers, its own attribute names, its own units, its own hierarchies — and machine-to-machine exchange collapses into one-off mappings.

IEC CDD solves this by providing:

  1. A single identifier per concept. Every class and property has an International Registration Data Identifier (IRDI) — for example, 0112/2///61360_4#AAD009 — that is globally unique, versioned, and language-independent. Two systems that cite the same IRDI are talking about the same concept.
  2. A multilingual terminology layer. Each property and class carries preferred_name, short_name, definition, note, and remark fields in every language the dictionary publishes.
  3. A versioned lineage. Each entity records its version, revision, status (proposal / draft / standard / superseded), responsible committee, and change-request history — so consumers can pin to a known version and reason about provenance.
  4. A machine-readable data model. Properties carry a data_type (REAL, INTEGER, STRING, ENUM, CLASS_REFERENCE, …) and a value_format (NR1 for integers, NR2 for reals, A for strings, …) so the wire representation is unambiguous.

The IEC 61360 series

IEC 61360 is published as a multi-part series. The parts most relevant to OpenCDD are:

Part Title (paraphrased)
IEC 61360-1 Definitions — Principles and methods. Foundational definitions, the dictionary model, classification principles.
IEC 61360-2 EXPRESS dictionary schema. The normative data model in EXPRESS.
IEC 61360-4 Reference dictionary. The actual published dictionary content (classes + properties) for electrotechnical components.
IEC 61360-6 Common data dictionary host integration.
IEC 61360-7 Data dictionary of cross-domain concepts (general items). Generic, reusable building blocks.

Other dictionaries — IEC 61987 (industrial-process measurement and control), IEC 62683 (low-voltage switchgear), IEC 63508 (miniature circuit-breakers) — are published as standalone standards but live inside the same CDD infrastructure and use the same IRDI scheme.

What’s in this browser

This site pre-renders every entity in six published dictionaries:

  • iec61360 — the IEC CDD reference dictionary itself.
  • iec61360-7 — cross-domain general items.
  • iec61987 — industrial-process measurement and control equipment.
  • iec62683 — low-voltage switchgear and controlgear.
  • iec63213 — power measurement applications in distribution networks.
  • iec63508 — miniature circuit-breakers (MCBs).

For every entity — class, property, value list, value term, unit, or relation — the browser renders its identifying attributes, semantic attributes (definition, note, remark, synonyms), administrative attributes (version, revision, status, responsible committee, publication date), and the full raw source payload from the IEC .xls export.

Where to read more