IEC 62541-3:2010

IEC 62541-3 ®
Edition 1.0 2010-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
OPC unified architecture –
Part 3: Address Space Model
Architecture unifiée OPC –
Partie 3: Modèle de l'espace d'adressage

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IEC 62541-3 ®
Edition 1.0 2010-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
OPC unified architecture –
Part 3: Address Space Model
Architecture unifiée OPC –
Partie 3: Modèle de l'espace d'adressage

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX XE
ICS 25.040.40; 35.100 ISBN 978-2-83220-310-1

– 2 – 62541-3  IEC:2010
CONTENTS
FOREWORD . 9
INTRODUCTION . 11
1 Scope . 12
2 Normative references . 12
3 Terms, definitions, abbreviations and conventions . 13
3.1 Terms and definitions . 13
3.2 Abbreviations . 14
3.3 Conventions . 14
3.3.1 Conventions for AddressSpace figures . 14
3.3.2 Conventions for defining NodeClasses . 14
4 AddressSpace concepts . 16
4.1 Overview . 16
4.2 Object Model . 16
4.3 Node Model . 16
4.3.1 General . 16
4.3.2 NodeClasses . 17
4.3.3 Attributes . 17
4.3.4 References . 17
4.4 Variables . 18
4.4.1 General . 18
4.4.2 Properties . 18
4.4.3 DataVariables . 18
4.5 TypeDefinitionNodes . 19
4.5.1 General . 19
4.5.2 Complex TypeDefinitionNodes and their InstanceDeclarations . 19
4.5.3 Subtyping . 20
4.5.4 Instantiation of complex TypeDefinitionNodes . 21
4.6 Event Model . 22
4.6.1 General . 22
4.6.2 EventTypes . 22
4.6.3 Event Categorization . 23
4.7 Methods . 23
5 Standard NodeClasses . 23
5.1 Overview . 23
5.2 Base NodeClass . 24
5.2.1 General . 24
5.2.2 NodeId . 24
5.2.3 NodeClass . 24
5.2.4 BrowseName . 24
5.2.5 DisplayName . 25
5.2.6 Description . 25
5.2.7 WriteMask . 25
5.2.8 UserWriteMask . 26
5.3 ReferenceType NodeClass . 26
5.3.1 General . 26
5.3.2 Attributes . 26

62541-3  IEC:2010 – 3 –
5.3.3 References . 28
5.4 View NodeClass . 28
5.5 Objects . 31
5.5.1 Object NodeClass . 31
5.5.2 ObjectType NodeClass . 33
5.5.3 Standard ObjectType FolderType . 35
5.5.4 Client-side creation of Objects of an ObjectType . 35
5.6 Variables . 35
5.6.1 General . 35
5.6.2 Variable NodeClass . 35
5.6.3 Properties . 39
5.6.4 DataVariable . 40
5.6.5 VariableType NodeClass . 40
5.6.6 Client-side creation of Variables of an VariableType . 42
5.7 Method NodeClass . 42
5.8 DataTypes . 44
5.8.1 DataType Model . 44
5.8.2 Encoding Rules for different kinds of DataTypes . 46
5.8.3 DataType NodeClass . 47
5.8.4 DataTypeDictionary, DataTypeDescription, DataTypeEncoding and
DataTypeSystem . 48
5.9 Summary of Attributes of the NodeClasses . 50
6 Type Model for ObjectTypes and VariableTypes . 51
6.1 Overview . 51
6.2 Definitions . 51
6.2.1 InstanceDeclaration . 51
6.2.2 Instances without ModellingRules . 51
6.2.3 InstanceDeclarationHierarchy . 51
6.2.4 Similar Node of InstanceDeclaration . 52
6.2.5 BrowsePath . 52
6.2.6 Attribute Handling of InstanceDeclarations . 52
6.2.7 Attribute Handling of Variable and VariableTypes . 52
6.3 Subtyping of ObjectTypes and VariableTypes . 52
6.3.1 Overview . 52
6.3.2 Attributes . 52
6.3.3 InstanceDeclarations . 53
6.4 Instances of ObjectTypes and VariableTypes . 56
6.4.1 Overview . 56
6.4.2 Creating an Instance . 56
6.4.3 Constraints on an Instance . 57
6.4.4 ModellingRules . 58
6.5 Changing Type Definitions that are already used . 64
6.6 ModelParent . 64
7 Standard ReferenceTypes . 65
7.1 General . 65
7.2 References ReferenceType . 66
7.3 HierarchicalReferences ReferenceType . 66
7.4 NonHierarchicalReferences ReferenceType . 67
7.5 HasChild ReferenceType . 67

– 4 – 62541-3  IEC:2010
7.6 Aggregates ReferenceType . 67
7.7 HasComponent ReferenceType . 67
7.8 HasProperty ReferenceType. 68
7.9 HasOrderedComponent ReferenceType . 68
7.10 HasSubtype ReferenceType . 68
7.11 Organizes ReferenceType . 68
7.12 HasModellingRule ReferenceType . 69
7.13 HasModelParent ReferenceType . 69
7.14 HasTypeDefinition ReferenceType . 69
7.15 HasEncoding ReferenceType . 69
7.16 HasDescription ReferenceType . 70
7.17 GeneratesEvent . 70
7.18 AlwaysGeneratesEvent . 70
7.19 HasEventSource . 70
7.20 HasNotifier . 71
8 Standard DataTypes . 72
8.1 General . 72
8.2 NodeId . 72
8.2.1 General . 72
8.2.2 NamespaceIndex . 72
8.2.3 IdentifierType . 73
8.2.4 Identifier value . 73
8.3 QualifiedName . 74
8.4 LocaleId . 74
8.5 LocalizedText . 74
8.6 Argument . 75
8.7 BaseDataType . 75
8.8 Boolean . 75
8.9 Byte . 75
8.10 ByteString . 75
8.11 DateTime . 76
8.12 Double . 76
8.13 Duration . 76
8.14 Enumeration . 76
8.15 Float . 76
8.16 Guid . 76
8.17 SByte . 76
8.18 IdType . 76
8.19 Image . 76
8.20 ImageBMP . 76
8.21 ImageGIF . 76
8.22 ImageJPG . 76
8.23 ImagePNG . 77
8.24 Integer . 77
8.25 Int16 . 77
8.26 Int32 . 77
8.27 Int64 . 77
8.28 TimeZoneDataType . 77
8.29 NamingRuleType . 77

62541-3  IEC:2010 – 5 –
8.30 NodeClass . 77
8.31 Number . 78
8.32 String . 78
8.33 Structure . 78
8.34 UInteger . 78
8.35 UInt16 . 78
8.36 UInt32 . 78
8.37 UInt64 . 78
8.38 UtcTime . 78
8.39 XmlElement . 78
9 Standard EventTypes . 79
9.1 General . 79
9.2 BaseEventType . 80
9.3 SystemEventType . 80
9.4 AuditEventType . 80
9.5 AuditSecurityEventType . 81
9.6 AuditChannelEventType . 82
9.7 AuditOpenSecureChannelEventType . 82
9.8 AuditSessionEventType . 82
9.9 AuditCreateSessionEventType . 82
9.10 AuditUrlMismatchEventType . 82
9.11 AuditActivateSessionEventType . 82
9.12 AuditCancelEventType . 82
9.13 AuditCertificateEventType . 82
9.14 AuditCertificateDataMismatchEventType . 82
9.15 AuditCertificateExpiredEventType . 82
9.16 AuditCertificateInvalidEventType . 83
9.17 AuditCertificateUntrustedEventType . 83
9.18 AuditCertificateRevokedEventType. 83
9.19 AuditCertificateMismatchEventType . 83
9.20 AuditNodeManagementEventType . 83
9.21 AuditAddNodesEventType . 83
9.22 AuditDeleteNodesEventType . 83
9.23 AuditAddReferencesEventType . 83
9.24 AuditDeleteReferencesEventType . 83
9.25 AuditUpdateEventType . 83
9.26 AuditWriteUpdateEventType . 83
9.27 AuditHistoryUpdateEventType . 84
9.28 AuditUpdateMethodEventType . 84
9.29 DeviceFailureEventType . 84
9.30 ModelChangeEvents . 84
9.30.1 General . 84
9.30.2 NodeVersion Property . 84
9.30.3 Views . 84
9.30.4 Event Compression . 84
9.30.5 BaseModelChangeEventType . 85
9.30.6 GeneralModelChangeEventType . 85
9.30.7 Guidelines for ModelChangeEvents . 85
9.31 SemanticChangeEventType . 85

– 6 – 62541-3  IEC:2010
9.31.1 General . 85
9.31.2 ViewVersion and NodeVersion Properties . 85
9.31.3 Views . 86
9.31.4 Event Compression . 86
Annex A (informative) How to use the Address Space Model . 87
Annex B (informative) OPC UA Meta Model in UML . 90
Annex C (normative) OPC Binary Type Description System . 100
Annex D (normative) Graphical Notation . 112
Bibliography . 117

Figure 1 – AddressSpace Node diagrams . 14
Figure 2 – OPC UA Object Model . 16
Figure 3 – AddressSpace Node Model . 17
Figure 4 – Reference Model . 18
Figure 5 – Example of a Variable Defined by a VariableType . 19
Figure 6 – Example of a Complex TypeDefinition . 20
Figure 7 – Object and its Components defined by an ObjectType . 21
Figure 8 – Symmetric and Non-Symmetric References . 27
Figure 9 – Variables, VariableTypes and their DataTypes . 44
Figure 10 – DataType Model . 45
Figure 11 – Example of DataType Modelling . 50
Figure 12 – Subtyping TypeDefinitionNodes. 53
Figure 13 – The Fully-Inherited InstanceDeclarationHierarchy for BetaType . 55
Figure 14 – An Instance and its TypeDefinitionNode . 56
Figure 15 – Example for several References between InstanceDeclarations . 58
Figure 16 – Example on changing instances based on InstanceDeclarations . 60
Figure 17 – Example on changing InstanceDeclarations based on an
InstanceDeclaration . 61
Figure 18 – Use of the Standard ModellingRule New . 62
Figure 19 – Example using the Standard ModellingRules Optional and Mandatory . 63
Figure 20 – Example on using ExposesItsArray . 64
Figure 21 – Complex example on using ExposesItsArray . 64
Figure 22 – Example on ModelParents . 65
Figure 23 – Standard ReferenceType Hierarchy . 66
Figure 24 – Event Reference Example . 71
Figure 25 – Complex Event Reference Example . 72
Figure 26 – Standard EventType Hierarchy . 79
Figure 27 – Audit Behaviour of a Server . 80
Figure 28 – Audit Behaviour of an Aggregating Server . 81
Figure B.1 – Background of OPC UA Meta Model . 90
Figure B.2 – Notation (I) . 91
Figure B.3 – Notation (II) . 91
Figure B.4 – BaseNode . 92
Figure B.5 – Reference and ReferenceType . 93

62541-3  IEC:2010 – 7 –
Figure B.6 – Predefined ReferenceTypes . 94
Figure B.7 – Attributes . 95
Figure B.8 – Object and ObjectType . 96
Figure B.9 – EventNotifier . 96
Figure B.10 – Variable and VariableType . 97
Figure B.11 – Method . 98
Figure B.12 – DataType . 99
Figure B.13 – View . 99
Figure C.1 – OPC Binary Dictionary Structure . 100
Figure D.1 – Example of a Reference connecting two Nodes . 113
Figure D.2 – Example of using a TypeDefinition inside a Node . 115
Figure D.3 – Example of exposing Attributes . 115
Figure D.4 – Example of exposing Properties inline . 116

Table 1 – NodeClass Table Conventions . 15
Table 2 – Base NodeClass . 24
Table 3 – Bit mask for WriteMask and UserWriteMask . 25
Table 4 – ReferenceType NodeClass . 26
Table 5 – View NodeClass . 30
Table 6 – Object NodeClass . 32
Table 7 – ObjectType NodeClass . 34
Table 8 – Variable NodeClass . 36
Table 9 – VariableType NodeClass . 41
Table 10 – Method NodeClass . 43
Table 11 – DataType NodeClass . 47
Table 12 – Overview about Attributes . 51
Table 13 – The InstanceDeclarationHierarchy for BetaType . 54
Table 14 – The Fully-Inherited InstanceDeclarationHierarchy for BetaType . 54
Table 15 – Rule for ModellingRules Properties when Subtyping . 59
Table 16 – Properties of ModellingRules . 61
Table 17 – NodeId Definition . 72
Table 18 – IdentifierType Values . 73
Table 19 – NodeId Null Values . 73
Table 20 – QualifiedName Definition . 74
Table 21 –LocaleId Examples . 74
Table 22 – LocalizedText Definition . 75
Table 23 – Argument Definition . 75
Table 24 – TimeZoneDataType Definition . 77
Table 25 – NamingRuleType Values . 77
Table 26 – NodeClass Values . 78
Table C.1 – TypeDictionary Components . 101
Table C.2 – TypeDescription Components . 102
Table C.3 – OpaqueType Components. 102

– 8 – 62541-3  IEC:2010
Table C.4 – EnumeratedType Components . 103
Table C.5 – StructuredType Components . 103
Table C.6 – FieldType Components . 104
Table C.7 – EnumeratedValue Components . 105
Table C.8 – ImportDirective Components . 105
Table C.9 – Standard Type Descriptions . 106
Table D.1 – Notation of Nodes depending on the NodeClass . 113
Table D.2 – Simple Notation of Nodes depending on the NodeClass . 114

62541-3  IEC:2010 – 9 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
OPC UNIFIED ARCHITECTURE –
Part 3: Address Space Model
FOREWORD
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9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62541-3 has been prepared by subcommittee 65E: Devices and
integration in enterprise systems of IEC technical committee 65: Industrial-process
measurement, control and automation.
This bilingual version (2012-10) corresponds to the monolingual English version, published in
2010-07.
The text of this standard is based on the following documents:
FDIS Report on voting
65E/160/FDIS 65E/164/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
The French version of this standard has not been voted upon.

– 10 – 62541-3  IEC:2010
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts of the IEC 62541 series, under the general title OPC Unified Architecture,
can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
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