IEC 62541-23:2025

Overview

IEC 62541-23:2025 defines a comprehensive set of common ReferenceTypes for use in industrial Information Models based on OPC Unified Architecture (OPC UA). These ReferenceTypes are more specific and practically focused than the foundational ones defined in IEC 62541-3, supporting more robust modelling of relationships and interactions within the OPC UA Address Space Model. Designed by the International Electrotechnical Commission (IEC), this standard enhances interoperability, structure, and clarity in industrial automation and digitalization projects where information consistency and semantic precision are essential.

Key Topics

IEC 62541-23:2025 introduces several new ReferenceTypes, each tailored to describe particular relationships among objects in industrial systems. Highlighted ReferenceTypes include:

• IsExecutableOn: Defines the connection between a software component and the execution environment it can run on, such as firmware and hardware mapping.
• IsExecutingOn: Indicates that a software component is actively running on a specific platform or environment.
• Controls: Relates a controller (like a PLC or software module) to the devices or objects under its management.
• Utilizes: Describes dependencies where a component requires the use of another, supporting both looping and non-looping relationships.
• Requires: Maps out non-hierarchical, acyclic dependencies needed for a component's operation, often among software and hardware building blocks.
• IsPhysicallyConnectedTo: Represents direct physical connections between hardware elements that are not in a subcomponent relationship.
• RepresentsSameEntityAs / HardwareAs / FunctionalityAs: Used when multiple OPC UA nodes model different facets or standards' views of the same real-world entity, hardware, or functionality.
• IsHostedBy: Associates a function or application with the environment or module required for its operation.

These ReferenceTypes significantly expand the expressiveness and utility of OPC UA Information Models, making industrial data exchanges and integrations more consistent and meaningful.

Applications

The ReferenceTypes defined in IEC 62541-23:2025 are vital for:

• Industrial automation systems: Model device dependencies, process control structures, hardware-software mappings, and real-time operational states.
• Asset management: Clarify relationships between equipment, firmware, and functionality for maintenance, diagnostics, and lifecycle management.
• Digital twins and virtual commissioning: Enable semantically rich and interoperable digital models of real manufacturing systems for simulation and analysis.
• Integration of heterogeneous systems: Support clear references between different vendors’ equipment, protocols, and standards through mutually understood reference relationships.
• OPC UA companion specifications: Leverage these ReferenceTypes to provide standardized links between information models from different domains (for example, mapping a robot’s motion axis to required powertrains or controls).

Implementers benefit from improved clarity, scalability, and traceability in complex OPC UA-enabled solutions, supporting agile manufacturing and Industry 4.0 environments.

Related Standards

To fully realize the value of IEC 62541-23:2025, use it with other significant standards in the OPC UA series:

• IEC 62541-1: OPC Unified Architecture – Overview and Concepts
• IEC 62541-3: OPC Unified Architecture – Address Space Model
• IEC 62541-5: OPC Unified Architecture – Information Model

These documents provide the foundational framework within which IEC 62541-23’s ReferenceTypes are deployed. For further definitions and guidance, consult the IEC Electropedia and companion OPC UA specifications tailored to industry-specific information modelling needs.

Keywords: OPC UA, ReferenceTypes, Information Models, industrial automation, IEC 62541-23, interoperability, digitalization, asset management, standards, OPC Unified Architecture, industrial connectivity.