SIST EN IEC 62541-5:2026

OPC unified architecture - Part 5: Information model (IEC 62541-5:2026)

IEC 62541-5:2026 This edition includes the following significant technical changes with respect to the previous edition:
a) Annex B has been removed and used to create IEC 62451-16;
b) Annex C has been removed and used to create IEC 62451-20;
c) currency information model has been added;
d) information model for Interfaces and AddIns has been added;
e) information model for Method Metadata has been added;
f) MaxSessions, MaxSubscriptions, and MaxMonitoredItems have been added to capabilities;
g) information model for ordered list of objects has been added;
h) PortableQualifiedName and PortableNodeId DataTypes have been added;
i) UriString DataType has been added;
j) SemanticVersionString DataType has been added;
k) AssociatedWith Reference Type has been added;
l) ConfigurationVersion Property has been added to NamespaceMetadataType;
m) AuditClientEventType and AuditClientUpdateMethodResultEventType have been added;
n) ModelVersion has been added to NamespaceMetadataType;
o) NoTransparentBackupRedundancyType has been added to support a Primary/Standby use case;
p) BitFieldType and BitFieldDefinitionType have been added.
This fourth edition cancels and replaces the third edition published in 2020. This edition constitutes a technical revision.

OPC Unified Architecture - Teil 5: Informationsmodell (IEC 62541-5:2026)

Architecture unifiée OPC - Partie 5: Modèle d'informations (IEC 62541-5:2026)

IEC 62541-5:2026 définit le Modèle d'information. Le Modèle d'information décrit des Nœuds normalisés de l'AddressSpace d'un Serveur. Ces Nœuds sont des types normalisés ainsi que des instances normalisées utilisés pour le diagnostic ou comme des points d'entrée à des Nœuds spécifiques au serveur. Ainsi, le Modèle d'information définit l'AddressSpace d'un Serveur OPC UA vide. Cependant, tous les Serveurs ne sont pas supposés fournir la totalité de ces Nœuds.
L'Annexe C normative définit le Système de description de Type OPC Binary.
L'Annexe B fait référence aux informations d'encodage pour les DataTypes personnalisés dans les versions précédentes du présent document.
Cette quatrième édition annule et remplace la troisième édition parue en 2020. Cette édition constitue une révision technique.
Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
a) l'Annexe B a été supprimée et utilisée afin de créer l'IEC 62451-16;
b) l'Annexe C a été supprimée et utilisée afin de créer l'IEC 62451-20;
c) un modèle d'information a été ajouté pour les Devises;
d) un modèle d'information a été ajouté pour les Interfaces et les AddIns;
e) un modèle d'information a été ajouté pour les Métadonnées de Méthode;
f) les capacités MaxSessions, MaxSubscriptions et MaxMonitoredItems ont été ajoutées;
g) un modèle d'information a été ajouté pour la liste ordonnée d'objets;
h) les DataTypes PortableQualifiedName et PortableNodeId ont été ajoutés;
i) le DataType UriString a été jouté;
j) le DataType SemanticVersionString a été ajouté;
k) le Type de Référence AssociatedWith a été ajouté;
l) la Propriété ConfigurationVersion a été ajoutée au NamespaceMetadataType;
m) l'AuditClientEventType et l'AuditClientUpdateMethodResultEventType ont été ajoutés;
n) la ModelVersion a été ajoutée au NamespaceMetadataType;
o) le NoTransparentBackupRedundancyType a été ajouté pour prendre en charge un cas d'utilisation primaire/de secours;
p) le BitFieldType et le BitFieldDefinitionType ont été ajoutés.

Enotna arhitektura OPC - 5. del: Informacijski model (IEC 62541-5:2026)

IEC 62541-5:2026 Ta izdaja vključuje naslednje pomembne tehnične spremembe v primerjavi s prejšnjo izdajo:
a) Priloga B je bila odstranjena in uporabljena za ustvarjanje IEC 62451-16;
b) Priloga C je bila odstranjena in uporabljena za ustvarjanje IEC 62451-20;
c) dodan je bil informacijski model za valute;
d) dodan je bil informacijski model za vmesnike (Interfaces) in dodatke (AddIns);
e) dodan je bil informacijski model za metapodatke metod (Method Metadata);
f) MaxSessions, MaxSubscriptions in MaxMonitoredItems so bili dodani k zmogljivostim;
g) dodan je bil informacijski model za urejen seznam objektov;
h) dodana sta bila podatkovna tipa (DataTypes) PortableQualifiedName in PortableNodeId;
i) dodan je bil podatkovni tip (DataType) UriString;
j) dodan je bil podatkovni tip (DataType) SemanticVersionString;
k) dodan je bil referenčni tip (Reference Type) AssociatedWith;
l) lastnost (Property) ConfigurationVersion je bila dodana k NamespaceMetadataType;
m) dodana sta bila AuditClientEventType in AuditClientUpdateMethodResultEventType;
n) ModelVersion je bil dodan k NamespaceMetadataType;
o) dodan je bil NoTransparentBackupRedundancyType za podporo primeru uporabe primarni/rezervni (Primary/Standby);
p) dodana sta bila BitFieldType in BitFieldDefinitionType.
Ta četrta izdaja razveljavlja in nadomešča tretjo izdajo, objavljeno leta 2020. Ta izdaja predstavlja tehnično revizijo.

General Information

• Status: Published
• Public Enquiry End Date: 21-Apr-2024
• Publication Date: 12-Apr-2026
• ICS: 25.040.40 - Industrial process measurement and control
• ICS: 35.100.05 - Multilayer applications
• ICS: 35.240.50 - IT applications in industry
• Technical Committee: MOV - Measuring equipment for electromagnetic quantities
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 24-Feb-2026
• Due Date: 01-May-2026
• Completion Date: 13-Apr-2026
• Mandate: M/490 - Standardisation mandate to the European Standardisation Organisations (ESOs) to support European Smart Grid deployment
• Ref Project: EN IEC 62541-5:2026 - OPC unified architecture - Part 5: Information Model

Relations

• Refers: SIST EN IEC 62541-9:2020 - OPC Unified Architecture - Part 9: Alarms and conditions (IEC 62541-9:2020)
• Effective Date: 20-Feb-2026
• Refers: SIST EN IEC 62541-3:2026 - OPC unified architecture - Part 3: Address space model (IEC 62541-3:2025)
• Effective Date: 20-Feb-2026
• Refers: SIST EN IEC 62541-18:2025 - OPC unified architecture - Part 18: Role-Based Security (IEC 62541-18:2025)
• Effective Date: 10-Feb-2026
• Refers: SIST EN IEC 62541-1:2026 - OPC unified architecture - Part 1: Overview and concepts (IEC 62541-1:2025)
• Effective Date: 10-Feb-2026
• Refers: SIST EN IEC 62541-8:2020 - OPC Unified Architecture - Part 8: Data Access (IEC 62541-8:2020)
• Effective Date: 10-Feb-2026
• Referred By: SIST EN 62541-4:2012 - OPC unified architecture - Part 4: Services (IEC 62541-4:2011)
• Effective Date: 20-Feb-2026
• Referred By: SIST EN 62541-6:2012 - OPC unified architecture - Part 6: Mappings (IEC 62541-6:2011)
• Effective Date: 20-Feb-2026
• Referred By: SIST EN 62769-1:2015 - Devices and integration in enterprise systems; Field Device Integration - Part 1: Overview (IEC 62769-1:2015)
• Effective Date: 20-Feb-2026
• Referred By: SIST EN IEC 62769-8:2023 - Field device integration (FDI®) - Part 8: EDD to OPC-UA Mapping (IEC 62769-8:2023)
• Effective Date: 20-Feb-2026
• Referred By: SIST EN 62769-3:2015 - Devices and integration in enterprise systems; Field Device Integration - Part 3: FDI Server (IEC 62769-3:2015)
• Effective Date: 20-Feb-2026
• Referred By: SIST EN IEC 62541-4:2020 - OPC Unified Architecture - Part 4: Services (IEC 62541-4:2020)
• Effective Date: 20-Feb-2026
• Referred By: SIST EN IEC 62769-1:2023 - Field Device Integration (FDI®) - Part 1: Overview (IEC 62769-1:2023)
• Effective Date: 20-Feb-2026
• Referred By: SIST EN IEC 62541-16:2026 - OPC unified architecture - Part 16: State machines (IEC 62541-16:2025)
• Effective Date: 20-Feb-2026
• Referred By: SIST EN IEC 62769-1:2021 - Field device integration (FDI) - Part 1: Overview (IEC 62769-1:2021)
• Effective Date: 20-Feb-2026
• Referred By: SIST EN 62541-13:2015 - OPC Unified Architecture -- Part 13: Aggregates (IEC 62541-13:2015)
• Effective Date: 20-Feb-2026

Overview

prEN IEC 62541-5:2024 (OPC Unified Architecture – Part 5: Information model) defines the information model used by OPC UA (IEC 62541). This committee draft for vote (CDV) specifies the structure and semantic rules for the OPC UA AddressSpace including NodeIds, BrowseNames, standard ObjectTypes, VariableTypes, EventTypes, Methods and standard Objects and Variables. The document is part of the IEC OPC UA family and targets industrial process measurement and control and IT applications in industry.

Key topics and technical requirements

• Node identification and naming
  • NodeIds and BrowseNames conventions to uniquely identify and navigate nodes in the AddressSpace.
• Common attributes
  • Attributes and usage rules for Objects, Variables, VariableTypes and Methods.
• Standard Types
  • Definitions for ObjectTypes (e.g., ServerType, ServerCapabilitiesType, ServerDiagnosticsType), VariableTypes, EventTypes (BaseEventType, AuditEventType and many audit/security event types) and InterfaceTypes.
• Standard Objects and Variables
  • Organisation of the AddressSpace (Root, Views, Types, DataTypes, EventTypes) and the Server Object model with diagnostics and metadata.
• Diagnostics and monitoring
  • Subscription, session and sampling diagnostics types, session security diagnostics, and diagnostics arrays.
• Modeling rules and methods
  • ModelingRuleType, FolderType, standard Methods (GetMonitoredItems, ResendData, SetSubscriptionDurable, RequestServerStateChange), and ModelChange events.
• Event modelling
  • Detailed EventType hierarchy covering audit, security, system, and model-change events.
• Conventions and normative structure
  • Terms, definitions, and conventions for node descriptions and data encodings.

These topics define requirements for consistent information modelling, interoperability, and semantic clarity across OPC UA implementations.

Applications and who uses it

• Industrial automation vendors and device manufacturers creating OPC UA servers and information models.
• System integrators and SCADA/IIoT architects who design interoperable data models across control systems.
• Software developers implementing OPC UA clients, servers, diagnostics and monitoring tools.
• Test labs and certification bodies validating conformance to OPC UA AddressSpace and semantic rules.
• Cybersecurity and asset management teams relying on standardized event and diagnostics models.

Use cases include asset modeling, telemetry and alarms, interoperable device integration, semantic data exchange in IIoT, and standardized diagnostics for maintenance and monitoring.

Related standards

• IEC 62541 series (other OPC UA parts: overview, address space, services, security, profiles). prEN IEC 62541-5 is Part 5 (Information model) and complements other parts that specify services, security, and mappings.

Keywords: OPC UA, IEC 62541-5, information model, NodeIds, BrowseNames, ObjectTypes, VariableTypes, EventTypes, AddressSpace, industrial automation, IIoT, interoperability.

Standards Content (Sample)

SLOVENSKI STANDARD
01-maj-2026
Enotna arhitektura OPC - 5. del: Informacijski model (IEC 62541-5:2026)
OPC unified architecture - Part 5: Information model (IEC 62541-5:2026)
OPC Unified Architecture - Teil 5: Informationsmodell (IEC 62541-5:2026)
Architecture unifiée OPC - Partie 5: Modèle d'informations (IEC 62541-5:2026)
Ta slovenski standard je istoveten z: EN IEC 62541-5:2026
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 62541-5

NORME EUROPÉENNE
EUROPÄISCHE NORM February 2026
ICS 25.040.40; 35.100.05 Supersedes EN IEC 62541-5:2020
English Version
OPC unified architecture - Part 5: Information Model
(IEC 62541-5:2026)
Architecture unifiée OPC - Partie 5: Modèle d'information OPC Unified Architecture - Teil 5: Informationsmodell
(IEC 62541-5:2026) (IEC 62541-5:2026)
This European Standard was approved by CENELEC on 2026-02-10. 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.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
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 62541-5:2026 E

European foreword
The text of document 65E/1062/CDV, future edition 4 of IEC 62541-5, 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
This document supersedes EN IEC 62541-5:2020 and all of its amendments and corrigenda (if any).
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.
This document has been prepared under a standardization request addressed to CENELEC by the
European Commission. The Standing Committee of the EFTA States subsequently approves these
requests for its Member States.
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 62541-5:2026 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 62541-11 NOTE Approved as EN IEC 62541-11
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 62541-4 - OPC unified architecture - Part 4: Services EN IEC 62541-4 -
IEC 62541-6 - OPC unified architecture - Part 6: EN IEC 62541-6 -
Mappings
IEC 62541-7 - OPC Unified Architecture - Part 7: Profiles EN IEC 62541-7 -
IEC 62541-8 - OPC unified architecture - Part 8: Data EN IEC 62541-8 -
access
IEC 62541-9 - OPC Unified Architecture - Part 9: Alarms EN IEC 62541-9 -
and Conditions
IEC 62541-18 - OPC unified architecture - Part 18: Role- EN IEC 62541-18 -
Based Security
IEC 62541-20 - OPC unified architecture - Part 20: File EN IEC 62541-20 -
transfer
ISO/IEC 11578 1996 Information technology - Open Systems - -
Interconnection - Remote Procedure Call
(RPC)
ISO/IEC/IEEE 2011 Information technology - Microprocessor - -
60559 Systems - Floating-Point arithmetic
IETF RFC 3629 - UTF-8, a transformation format of ISO - -
IETF RFC 3986 - Uniform Resource Identifier (URI): Generic - -
Syntax
- Semantic Versioning 2.0.0 - -

- Unicode Character Database - -

IEC 62541-5 ®
Edition 4.0 2026-01
INTERNATIONAL
STANDARD
OPC unified architecture -
Part 5: Information Model
ICS 25.040.40; 35.100.05 ISBN 978-2-8327-0878-1

IEC 62541-5:2026-01(en)
IEC 62541-5:2026 © IEC 2026
CONTENTS
FOREWORD . 15
1 Scope . 17
2 Normative references . 17
3 Terms, definitions, abbreviated terms and conventions . 18
3.1 Terms and definitions . 18
3.2 Abbreviated terms. 18
3.3 Conventions for Node descriptions . 18
4 NodeIds and BrowseNames . 20
4.1 NodeIds . 20
4.2 BrowseNames . 21
5 Common Attributes . 21
5.1 General . 21
5.2 Objects . 21
5.3 Variables . 21
5.4 VariableTypes . 22
5.5 Methods . 22
6 Standard ObjectTypes . 23
6.1 General . 23
6.2 BaseObjectType . 23
6.3 ObjectTypes for the Server Object . 23
6.3.1 ServerType . 23
6.3.2 ServerCapabilitiesType . 26
6.3.3 ServerDiagnosticsType . 30
6.3.4 SessionsDiagnosticsSummaryType . 31
6.3.5 SessionDiagnosticsObjectType . 32
6.3.6 VendorServerInfoType . 32
6.3.7 ServerRedundancyType . 33
6.3.8 TransparentRedundancyType . 33
6.3.9 NonTransparentRedundancyType . 34
6.3.10 NonTransparentNetworkRedundancyType . 34
6.3.11 OperationLimitsType . 35
6.3.12 AddressSpaceFileType . 37
6.3.13 NamespaceMetadataType. 37
6.3.14 NamespacesType . 39
6.3.15 NonTransparentBackupRedundancyType . 40
6.4 ObjectTypes used as EventTypes . 41
6.4.1 General. 41
6.4.2 BaseEventType . 41
6.4.3 AuditEventType . 45
6.4.4 AuditSecurityEventType . 46
6.4.5 AuditChannelEventType . 46
6.4.6 AuditOpenSecureChannelEventType . 47
6.4.7 AuditSessionEventType . 48
6.4.8 AuditCreateSessionEventType . 48
6.4.9 AuditUrlMismatchEventType . 49
6.4.10 AuditActivateSessionEventType . 50
IEC 62541-5:2026 © IEC 2026
6.4.11 AuditCancelEventType . 50
6.4.12 AuditCertificateEventType . 51
6.4.13 AuditCertificateDataMismatchEventType . 51
6.4.14 AuditCertificateExpiredEventType . 52
6.4.15 AuditCertificateInvalidEventType . 52
6.4.16 AuditCertificateUntrustedEventType . 53
6.4.17 AuditCertificateRevokedEventType . 53
6.4.18 AuditCertificateMismatchEventType . 54
6.4.19 AuditNodeManagementEventType . 54
6.4.20 AuditAddNodesEventType . 55
6.4.21 AuditDeleteNodesEventType . 55
6.4.22 AuditAddReferencesEventType . 56
6.4.23 AuditDeleteReferencesEventType. 56
6.4.24 AuditUpdateEventType . 57
6.4.25 AuditWriteUpdateEventType . 57
6.4.26 AuditHistoryUpdateEventType . 58
6.4.27 AuditUpdateMethodEventType . 59
6.4.28 SystemEventType . 59
6.4.29 DeviceFailureEventType . 60
6.4.30 SystemStatusChangeEventType . 60
6.4.31 BaseModelChangeEventType . 61
6.4.32 GeneralModelChangeEventType . 61
6.4.33 SemanticChangeEventType . 62
6.4.34 EventQueueOverflowEventType . 62
6.4.35 ProgressEventType . 63
6.4.36 AuditClientEventType . 64
6.4.37 AuditClientUpdateMethodResultEventType . 64
6.5 ModellingRuleType . 65
6.6 FolderType . 65
6.7 DataTypeEncodingType . 65
6.8 AggregateFunctionType . 66
6.9 BaseInterfaceType . 66
6.10 OrderedListType . 67
6.11 IOrderedObjectType Definition . 67
7 Standard VariableTypes . 68
7.1 General . 68
7.2 BaseVariableType . 68
7.3 PropertyType . 69
7.4 BaseDataVariableType . 69
7.5 ServerVendorCapabilityType. 70
7.6 ServerStatusType . 70
7.7 BuildInfoType . 71
7.8 ServerDiagnosticsSummaryType . 72
7.9 SamplingIntervalDiagnosticsArrayType . 72
7.10 SamplingIntervalDiagnosticsType . 73
7.11 SubscriptionDiagnosticsArrayType . 73
7.12 SubscriptionDiagnosticsType . 74
7.13 SessionDiagnosticsArrayType . 75
7.14 SessionDiagnosticsVariableType . 76
IEC 62541-5:2026 © IEC 2026
7.15 SessionSecurityDiagnosticsArrayType . 79
7.16 SessionSecurityDiagnosticsType . 79
7.17 OptionSetType . 80
7.18 SelectionListType . 81
7.19 AudioVariableType. 82
7.20 RationalNumberType . 83
7.21 VectorType . 83
7.22 3DVectorType . 83
7.23 CartesianCoordinatesType . 84
7.24 3DCartesianCoordinatesType . 84
7.25 OrientationType . 85
7.26 FrameType . 85
7.27 BitFieldType . 86
8 Standard Objects and their Variables . 87
8.1 General . 87
8.2 Objects used to organise the AddressSpace structure . 87
8.2.1 Overview . 87
8.2.2 Root . 88
8.2.3 Views . 88
8.2.4 Objects . 89
8.2.5 Types . 90
8.2.6 ObjectTypes . 90
8.2.7 VariableTypes . 91
8.2.8 ReferenceTypes . 92
8.2.9 DataTypes. 92
8.2.10 EventTypes . 93
8.2.11 InterfaceTypes . 94
8.2.12 Locations . 94
8.3 Server Object and its containing Objects . 95
8.3.1 General. 95
8.3.2 Server Object . 96
8.4 ModellingRule Objects . 99
8.4.1 ExposesItsArray. 99
8.4.2 Mandatory . 99
8.4.3 Optional . 99
8.4.4 OptionalPlaceholder . 99
8.4.5 MandatoryPlaceholder . 100
9 Standard Methods . 100
9.1 GetMonitoredItems . 100
9.2 ResendData . 101
9.3 SetSubscriptionDurable . 102
9.4 RequestServerStateChange . 103
10 Standard Views . 104
11 Standard ReferenceTypes . 104
11.1 References . 104
11.2 HierarchicalReferences . 104
11.3 NonHierarchicalReferences . 105
11.4 HasChild . 105
IEC 62541-5:2026 © IEC 2026
11.5 Aggregates . 105
11.6 Organizes . 106
11.7 HasComponent . 106
11.8 HasOrderedComponent . 107
11.9 HasProperty . 107
11.10 HasSubtype . 107
11.11 HasModellingRule . 108
11.12 HasTypeDefinition . 108
11.13 HasEncoding . 109
11.14 HasEventSource . 109
11.15 HasNotifier . 109
11.16 GeneratesEvent. 110
11.17 AlwaysGeneratesEvent . 110
11.18 HasArgumentDescription . 111
11.19 HasOptionalInputArgumentDescription . 111
11.20 HasInterface . 111
11.21 HasAddIn . 112
11.22 IsDeprecated. 112
11.23 HasStructuredComponent . 113
11.24 AssociatedWith. 113
11.25 HasKeyValueDescription . 113
12 Standard DataTypes . 114
12.1 General . 114
12.2 DataTypes defined in IEC 62541-3 . 114
12.2.1 BaseDataType . 114
12.2.2 Boolean . 114
12.2.3 ByteString . 115
12.2.4 DateTime . 117
12.2.5 Enumeration . 118
12.2.6 Guid . 119
12.2.7 LocalizedText . 119
12.2.8 NodeId . 120
12.2.9 Number . 120
12.2.10 QualifiedName . 125
12.2.11 String . 126
12.2.12 Structure . 128
12.2.13 XmlElement . 132
12.3 DataTypes defined in IEC 62541-4 . 133
12.3.1 AddNodesItem . 133
12.3.2 AddReferencesItem . 133
12.3.3 ApplicationDescription . 133
12.3.4 ContentFilter . 134
12.3.5 DataValue . 134
12.3.6 DeleteNodesItem . 134
12.3.7 DeleteReferencesItem . 135
12.3.8 DiagnosticInfo . 135
12.3.9 ExpandedNodeId . 135
12.3.10 MessageSecurityMode . 136
12.3.11 NumericRange . 136
IEC 62541-5:2026 © IEC 2026
12.3.12 SecurityTokenRequestType . 136
12.3.13 SignedSoftwareCertificate . 137
12.3.14 StatusCode . 137
12.3.15 UserIdentityToken . 137
12.3.16 VersionTime . 139
12.4 BuildInfo . 139
12.5 RedundancySupport. 140
12.6 ServerState . 141
12.7 RedundantServerDataType . 142
12.8 SamplingIntervalDiagnosticsDataType . 142
12.9 ServerDiagnosticsSummaryDataType . 143
12.10 ServerStatusDataType . 144
12.11 SessionDiagnosticsDataType . 145
12.12 SessionSecurityDiagnosticsDataType . 147
12.13 ServiceCounterDataType . 148
12.14 StatusResult . 149
12.15 SubscriptionDiagnosticsDataType . 150
12.16 ModelChangeStructureDataType . 151
12.17 SemanticChangeStructureDataType . 153
12.18 BitFieldMaskDataType . 153
12.19 NetworkGroupDataType . 154
12.20 EndpointUrlListDataType . 154
12.21 KeyValuePair . 155
12.22 RationalNumber. 155
12.23 Vector . 156
12.24 3DVector . 156
12.25 CartesianCoordinates. 157
12.26 3DCartesianCoordinates . 157
12.27 Orientation . 158
12.28 Frame . 158
12.29 DataTypeSchemaHeader . 159
12.30 DataTypeDescription . 160
12.31 StructureDescription . 160
12.32 EnumDescription . 161
12.33 SimpleTypeDescription . 161
12.34 UABinaryFileDataType . 162
12.35 PortableQualifiedName . 163
12.36 PortableNodeId . 163
12.37 UriString . 164
12.38 UnsignedRationalNumber . 164
12.39 SemanticVersionString DataType . 165
12.40 Handle. 167
12.41 TrimmedString . 167
12.42 RedundantServerMode . 167
12.43 BitFieldDefinition . 168
12.43.1 Type Definition . 168
12.43.2 Example (informative). 169
Annex A (informative) Design decisions when modelling the server information . 172
A.1 Overview . 172
IEC 62541-5:2026 © IEC 2026
A.2 ServerType and Server Object . 172
A.3 Typed complex Objects beneath the Server Object . 172
A.4 Properties versus DataVariables . 172
A.5 Complex Variables using complex DataTypes . 173
A.6 Complex Variables having an array . 173
A.7 Redundant information . 173
A.8 Usage of the BaseDataVariableType . 174
A.9 Subtyping . 174
A.10 Extensibility mechanism . 174
Annex B (informative) DataTypeDictionary . 175
B.1 Overview . 175
Annex C (informative) OPC Binary Type Description System . 176
C.1 Concepts . 176
C.2 Schema description . 177
C.2.1 TypeDictionary . 177
C.2.2 TypeDescription . 177
C.2.3 OpaqueType. 178
C.2.4 EnumeratedType . 178
C.2.5 StructuredType . 179
C.2.6 FieldType . 179
C.2.7 EnumeratedValue . 181
C.2.8 ByteOrder . 182
C.2.9 ImportDirective . 182
C.3 Standard Type descriptions . 182
C.4 Type Description examples . 183
C.5 OPC Binary XML schema . 185
C.6 OPC Binary Standard TypeDictionary . 186
Bibliography . 189

Figure 1 – Standard AddressSpace structure . 87
Figure 2 – Views organization . 88
Figure 3 – Objects organization . 89
Figure 4 – ObjectTypes organization . 90
Figure 5 – VariableTypes organization . 91
Figure 6 – ReferenceType definitions . 92
Figure 7 – EventTypes organization . 93
Figure 8 – InterfaceTypes Organization . 94
Figure 9 – Locations organization. 95
Figure 10 – Excerpt of diagnostic information of the Server. 96
Figure 11 – MyBitFieldType Example Illustration . 170
Figure 12 – MyBitFieldArrayType Example Illustration . 171
Figure C.1 – OPC Binary Dictionary structure . 176

Table 1 – Examples of DataTypes . 19
Table 2 – TypeDefinition Table . 20
Table 3 – Common Node Attributes . 21
IEC 62541-5:2026 © IEC 2026
Table 4 – Common Object Attributes . 21
Table 5 – Common Variable Attributes . 22
Table 6 – Common VariableType Attributes . 22
Table 7 – Common Method Attributes . 22
Table 8 – BaseObjectType definition . 23
Table 9 – ServerType definition . 24
Table 10 – ServerCapabilitiesType definition . 27
Table 11 – ServerDiagnosticsType definition . 30
Table 12 – SessionsDiagnosticsSummaryType definition . 31
Table 13 – SessionDiagnosticsObjectType definition . 32
Table 14 – VendorServerInfoType definition . 32
Table 15 – ServerRedundancyType definition . 33
Table 16 – TransparentRedundancyType definition . 33
Table 17 – NonTransparentRedundancyType definition . 34
Table 18 – NonTransparentNetworkRedundancyType definition . 34
Table 19 – OperationLimitsType definition. 35
Table 20 – AddressSpaceFileType definition . 37
Table 21 – NamespaceMetadataType definition . 38
Table 22 – NamespacesType definition . 40
Table 23 – NonTransparentBackupRedundancyType definition . 40
Table 24 – BaseEventType definition . 42
Table 25 – AuditEventType definition. 45
Table 26 – AuditSecurityEventType definition . 46
Table 27 – AuditChannelEventType definition . 46
Table 28 – AuditOpenSecureChannelEventType definition . 47
Table 29 – AuditSessionEventType definition . 48
Table 30 – AuditCreateSessionEventType definition . 49
Table 31 – AuditUrlMismatchEventType definition . 49
Table 32 – AuditActivateSessionEventType definition. 50
Table 33 – AuditCancelEventType definition. 51
Table 34 – AuditCertificateEventType definition . 51
Table 35 – AuditCertificateDataMismatchEventType definition . 52
Table 36 – AuditCertificateExpiredEventType definition . 52
Table 37 – AuditCertificateInvalidEventType definition . 53
Table 38 – AuditCertificateUntrustedEventType definition . 53
Table 39 – AuditCertificateRevokedEventType definition . 54
Table 40 – AuditCertificateMismatchEventType definition . 54
Table 41 – AuditNodeManagementEventType definition . 55
Table 42 – AuditAddNodesEventType definition . 55
Table 43 – AuditDeleteNodesEventType definition . 56
Table 44 – AuditAddReferencesEventType definition . 56
Table 45 – AuditDeleteReferencesEventType definition . 57
Table 46 – AuditUpdateEventType definition . 57
SIST EN IEC 62541-5
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