SIST EN IEC 62541-23:2026

SLOVENSKI STANDARD
01-maj-2026
Enotna arhitektura OPC - 23. del: Skupni tipi zvez (IEC 62541-23:2025)
OPC unified architecture - Part 23: Common reference types (IEC 62541-23:2025)
OPC Unified Architecture – Teil 23: Gemeinsame Referenztypen (IEC 62541-23:2025)
Architecture unifiée OPC - Partie 23: Referencetypes communs (IEC 62541-23:2025)
Ta slovenski standard je istoveten z: EN IEC 62541-23:2026
ICS:
25.040.40 Merjenje in krmiljenje Industrial process
industrijskih postopkov measurement and control
35.240.50 Uporabniške rešitve IT v IT applications in industry
industriji
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 62541-23

NORME EUROPÉENNE
EUROPÄISCHE NORM February 2026
ICS 25.040
English Version
OPC unified architecture - Part 23: Common ReferenceTypes
(IEC 62541-23:2025)
Architecture unifiée OPC - Partie 23: ReferenceTypes OPC Unified Architecture - Teil 23: Gemeinsame
communs Referenztypen
(IEC 62541-23:2025) (IEC 62541-23:2025)
This European Standard was approved by CENELEC on 2026-01-27. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
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Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Türkiye and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 62541-23:2026 E

European foreword
The text of document 65E/1048/CDV, future edition 1 of IEC 62541-23, prepared by SC 65E "Devices
and integration in enterprise systems" of IEC/TC 65 "Industrial-process measurement, control and
automation" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2027-02-28
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2029-02-28
document have to be withdrawn
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 62541-23:2025 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following note has to be added for the standard indicated:
IEC 62541-100 NOTE Approved as EN 62541-100
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments)
applies.
NOTE 1  Where an International Publication has been modified by common modifications, indicated by (mod),
the relevant EN/HD applies.
NOTE 2  Up-to-date information on the latest versions of the European Standards listed in this annex is available
here: www.cencenelec.eu.
Publication Year Title EN/HD Year
IEC 62541-1 - OPC Unified Architecture - Part 1: EN IEC 62541-1 -
Overview and concepts
IEC 62541-3 - OPC Unified Architecture - Part 3: Address EN IEC 62541-3 -
Space Model
IEC 62541-5 - OPC Unified architecture - Part 5: EN IEC 62541-5 -
Information Model
IEC 62541-23 ®
Edition 1.0 2025-12
INTERNATIONAL
STANDARD
OPC unified architecture -
Part 23: Common ReferenceTypes
ICS 25.040  ISBN 978-2-8327-0837-8

IEC 62541-23:2025-12(en)
IEC 62541-23:2025 © IEC 2025
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms, definitions and abbreviated terms . 5
3.1 Terms and definitions . 5
3.2 Abbreviated terms. 5
4 OPC UA ReferenceTypes . 5
4.1 Overview . 5
4.2 IsExecutableOn . 6
4.2.1 Overview . 6
4.2.2 Definition . 6
4.3 IsExecutingOn . 7
4.3.1 Overview . 7
4.3.2 Definition . 7
4.4 Controls . 8
4.4.1 Overview . 8
4.4.2 Definition . 8
4.5 Utilizes . 9
4.5.1 Overview . 9
4.5.2 Definition . 9
4.6 Requires . 9
4.6.1 Overview . 9
4.6.2 Definition . 10
4.7 IsPhysicallyConnectedTo. 10
4.7.1 Overview . 10
4.7.2 Definition . 10
4.8 RepresentsSameEntityAs . 11
4.8.1 Overview . 11
4.8.2 Definition . 11
4.9 RepresentsSameHardwareAs . 12
4.9.1 Overview . 12
4.9.2 Definition . 12
4.10 RepresentsSameFunctionalityAs . 13
4.10.1 Overview . 13
4.10.2 Definition . 13
4.11 IsHostedBy . 14
4.11.1 Overview . 14
4.11.2 Definition . 14
4.12 HasPhysicalComponent. 14
4.12.1 Overview . 14
4.12.2 Definition . 15
4.13 HasContainedComponent . 15
4.13.1 Overview . 15
4.13.2 Definition . 15
4.14 HasAttachedComponent . 16
4.14.1 Overview . 16
4.14.2 Definition . 16
IEC 62541-23:2025 © IEC 2025
5 Reference Description . 17
5.1 Overview . 17
5.2 Reference refinement . 18
5.3 OPC UA VariableTypes . 20
5.3.1 Overview . 20
5.3.2 ReferenceDescriptionVariableType . 20
5.4 OPC UA ReferenceTypes . 20
5.4.1 Overview . 20
5.4.2 HasReferenceDescription . 20
5.5 OPC UA DataTypes . 21
5.5.1 ReferenceDescriptionDataType . 21
5.5.2 ReferenceListEntryDataType . 22
Annex A (informative) ReferenceDescription Design Decisions . 23
A.1 Overview . 23
A.2 Alternative Approach: Intermediate Object. 23
Bibliography . 24

Figure 1 – Overview of ReferenceTypes . 6
Figure 2 – Example of ReferenceDescriptions . 17
Figure 3 – Examples of Reference refinements . 18
Figure 4 – Example of Reference refinements with multiple path options . 18
Figure 5 – Example of how to use Reference refinements . 19
Figure 6 – Example of how to use Reference refinements with two levels and multiple
hops. 19
Figure A.1 – Refinement of References by Proxy Object . 23

Table 1 – IsExecutableOn definition . 7
Table 2 – IsExecutingOn definition . 8
Table 3 – Controls definition . 8
Table 4 – Utilizes definition . 9
Table 5 – Requires definition . 10
Table 6 – IsPhysicallyConnectedTo definition . 11
Table 7 – RepresentsSameEntityAs definition . 12
Table 8 – RepresentsSameHardwareAs definition . 13
Table 9 – RepresentsSameFunctionalityAs definition . 13
Table 10 – IsHostedBy definition . 14
Table 11 – HasPhysicalComponent definition . 15
Table 12 – HasContainedComponent definition . 16
Table 13 – HasAttachedComponent definition . 16
Table 14 – ReferenceDescriptionVariableType definition . 20
Table 15 – HasReferenceDescription definition . 21
Table 16 – ReferenceDescriptionDataType structure . 21
Table 17 – ReferenceDescriptionDataType definition . 22
Table 18 – ReferenceListEntryDataType structure . 22
Table 19 – ReferenceListEntryDataType definition . 22
IEC 62541-23:2025 © IEC 2025
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
OPC unified architecture -
Part 23: Common ReferenceTypes

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as "IEC Publication(s)"). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC 62541-23 has been prepared by subcommittee 65E: Devices and integration in enterprise
systems, of IEC technical committee 65: Industrial-process measurement, control, and
automation. It is an International Standard.
The text of this International Standard is based on the following documents:
Draft Report on voting
65E/1048/CDV 65E/1105/RVC
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
IEC 62541-23:2025 © IEC 2025
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
Throughout this document and the other Parts of the series, certain document conventions are
used:
Italics are used to denote a defined term or definition that appears in the "Terms and definitions"
clause in one of the parts of the series.
Italics are also used to denote the name of a service input or output parameter or the name of
a structure or element of a structure that are usually defined in tables.
The italicized terms and names are also often written in camel-case (the practice of writing
compound words or phrases in which the elements are joined without spaces, with each
element's initial letter capitalized within the compound). For example, the defined term is
AddressSpace instead of Address Space. This makes it easier to understand that there is a
single definition for AddressSpace, not separate definitions for Address and Space.
A list of all parts of the IEC 62541 series, published under the general title OPC Unified
Architecture, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
– reconfirmed,
– withdrawn, or
– revised.
IEC 62541-23:2025 © IEC 2025
1 Scope
This part of IEC 62541 defines ReferenceTypes commonly used in industrial Information
Models. They are more specific than the ReferenceTypes in IEC 62541-3 which are an inherent
part of the OPC UA Address Space Model.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 62541-1, OPC Unified Architecture - Part 1: Overview and Concepts
IEC 62541-3, OPC Unified Architecture - Part 3: Address Space Model
IEC 62541-5, OPC Unified Architecture - Part 5: Information Model
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 62541-1,
IEC 62541-3, and IEC 62541-5 apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
– IEC Electropedia: available at https://www.electropedia.org/
– ISO Online browsing platform: available at https://www.iso.org/obp
3.2 Abbreviated terms
CPU Central Processing Unit
IO Input/Output
IP Internet Protocol
PC Personal Computer
PCI Peripheral Component Interconnect
PHY Physical Layer
PLC Programmable Logic Controller
RFID Radio Frequency Identification
4 OPC UA ReferenceTypes
4.1 Overview
Figure 1 gives an overview of the ReferenceTypes defined in the following subsections.
IEC 62541-23:2025 © IEC 2025
Figure 1 – Overview of ReferenceTypes
4.2 IsExecutableOn
4.2.1 Overview
This ReferenceType can be used to expose the relation between a software component and its
execution environment. For example, it can be used to expose which firmware (including its
version) is available on a field device.
4.2.2 Definition
The IsExecutableOn is a concrete ReferenceType and can be used directly. It is a subtype of
NonHierarchicalReferences.
The semantic of this ReferenceType is to relate a software component to its execution
environment that is required to run the software (e.g. Hardware component, Task or Thread).
The relationship shows that the execution environment the reference points to, is able to
execute the software component. This does not imply that the software component is currently
being executed or running. To show that the software is running in an environment,
IsExecutingOn should be used.
The SourceNode of References of this ReferenceType shall be an Object or ObjectType
representing a software component.
The TargetNode of References of this ReferenceType shall be an Object or ObjectType
representing an execution environment for a software component, which can be a piece of
hardware (e.g. Device) or some other environment like a task, thread, or software execution
framework.
IsExecutableOn is formally defined in Table 1.
IEC 62541-23:2025 © IEC 2025
Table 1 – IsExecutableOn definition
Attributes Value
BrowseName IsExecutableOn
InverseName CanExecute
Symmetric FALSE
IsAbstract FALSE
References NodeClass BrowseName Comment
Subtype of NonHierarchicalReferences defined in IEC 62541-5
Conformance Units
Base Info IsExecutableOn
4.3 IsExecutingOn
4.3.1 Overview
This ReferenceType can be used to expose the relation between a software component and its
execution environment it is currently executing on. References of this ReferenceType can be
very dynamic and will disappear as soon as the software component is not being executed
anymore. For example, it can be used to expose that a PLC program is currently running on a
specific task of a PLC.
4.3.2 Definition
The IsExecutingOn is a concrete ReferenceType and can be used directly. It is a subtype of
Utilizes.
The semantic of this ReferenceType is to relate a software component to its execution
environment it is currently executing on (e.g. Hardware component, Task or Thread).
References of this ReferenceType shall only be used when the software component is currently
executed / running.
The SourceNode of References of this ReferenceType shall be an Object or ObjectType
representing a software component.
The TargetNode of References of this ReferenceType shall be an Object or ObjectType
representing an execution environment for a software component, which can be a piece of
hardware (e.g. Device) or some other environment like a task, thread or software execution
framework.
IsExecutingOn is formally defined in Table 2.
IEC 62541-23:2025 © IEC 2025
Table 2 – IsExecutingOn definition
Attributes Value
BrowseName IsExecutingOn
InverseName Executes
Symmetric FALSE
IsAbstract FALSE
References NodeClass BrowseName Comment
Subtype of Utilizes defined in 4.5
Conformance Units
Base Info IsExecutingOn
4.4 Controls
4.4.1 Overview
This ReferenceType can be used to expose the relation between an object controlling other
objects and the controlled objects. For example, it can be used to relate a PLC to the field
devices or machine-modules controlled by the PLC or a software component to the hardware
components controlled by the software component.
4.4.2 Definition
The Controls is a concrete ReferenceType and can be used directly. It is a subtype of
HierarchicalReferences.
The semantic of this ReferenceType is to relate the controlling component to the components
controlled by the controlling component.
The SourceNode of References of this ReferenceType shall be an Object or ObjectType
representing the controlling component, as for example a PLC or a software component.
The TargetNode of References of this ReferenceType shall be an Object representing a
component that is controlled by the TargetNode.
Controls is formally defined in Table 3.
Table 3 – Controls definition
Attributes Value
BrowseName Controls
InverseName IsControlledBy
Symmetric FALSE
IsAbstract FALSE
References NodeClass BrowseName Comment
Subtype of HierarchicalReferences defined in IEC 62541-5
Conformance Units
Base Info Controls
IEC 62541-23:2025 © IEC 2025
4.5 Utilizes
4.5.1 Overview
This ReferenceType can be used to expose the relation between a component to other
components, that the component needs in order to work. In contrast to the Requires
ReferenceType, this non-hierarchical ReferenceType allows loops, e.g. both components need
each other in order to work. In that case, there would be two References, the first one pointing
from one component to the oth
...