EN IEC 62541-8:2020

OPC Unified Architecture - Part 8: Data Access

IEC 62541-8:2020 is available as IEC 62541-8:2020 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.IEC 62541-8:2020 is part of the overall OPC Unified Architecture (OPC UA) standard series and defines the information model associated with Data Access (DA). It particularly includes additional VariableTypes and complementary descriptions of the NodeClasses and Attributes needed for Data Access, additional Properties, and other information and behaviour. The complete address space model, including all NodeClasses and Attributes is specified in IEC 62541-3. The services to detect and access data are specified in IEC 62541-4. This third edition cancels and replaces the second edition published in 2015. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) added new VariableTypes for AnalogItems; b) added an Annex that specifies a recommended mapping of OPC UA Dataccess to OPC COM DataAccess; c) changed the ambiguous description of "Bad_NotConnected"; d) updated description for EUInformation to refer to latest revision of UNCEFACT units.

OPC Unified Architecture – Teil 8: Zugriff auf Automatisierungsdaten

Architecture unifiée OPC - Partie 8: Accès aux données

IEC 62541-8:2020 est disponible sous forme de IEC 62541-8:2020 RLV qui contient la Norme internationale et sa version Redline, illustrant les modifications du contenu technique depuis l'édition précédente.L'IEC 62541-8:2020 fait partie intégrante de la série de normes générales sur l'architecture unifiée OPC (OPC UA). Elle définit le modèle d'information associé à l'Accès aux données (DA). Elle spécifie notamment des VariableTypes supplémentaires et fournit des descriptions complémentaires concernant les NodeClasses et attributs nécessaires pour l'Accès aux données, ainsi que des propriétés supplémentaires et d'autres paramètres relatifs aux informations et au comportement. Le modèle d'espace d'adresses complet, comprenant toutes les NodeClasses et tous les Attributs, est spécifié dans l'IEC 62541-3. Les services de détection et d'accès aux données sont spécifiés dans l'IEC 62541-4. Cette troisième édition annule et remplace la deuxième édition parue en 2015. Cette édition constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente: a) ajout de nouveaux VariableTypes pour les AnalogItems; b) ajout d'une annexe qui spécifie le mapping recommandé entre OPC UA DataAccess et OPC COM DataAccess; c) modification de la description ambiguë de "Bad_NotConnected"; d) mise à jour de la description de EUInformation pour renvoyer à la dernière révision des unités CEFACT-ONU.

Enotna arhitektura OPC - 8. del: Dostop do podatkov (IEC 62541-8:2020)

General Information

• Status: Published
• Publication Date: 06-Aug-2020
• ICS: 25.040.40 - Industrial process measurement and control
• ICS: 35.100 - Open systems interconnection (OSI)
• ICS: 35.100.05 - Multilayer applications
• Technical Committee: CLC/TC 65X - Industrial-process measurement, control and automation
• Drafting Committee: IEC/SC 65E - IEC_SC_65E
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 07-Aug-2020
• Completion Date: 07-Aug-2020
• Mandate: M/490 - Standardisation mandate to the European Standardisation Organisations (ESOs) to support European Smart Grid deployment
• Ref Project: SIST EN IEC 62541-8:2020 - OPC Unified Architecture - Part 8: Data Access (IEC 62541-8:2020)

Relations

• Replaces: EN 45510-2-9:2008 - Guide for procurement of power station equipment - Part 2-9: Electrical equipment - Cabling systems
• Effective Date: 07-Jun-2022
• Revised: prEN IEC 62541-8:2024 - OPC unified architecture - Part 8: Data access
• Effective Date: 31-Jan-2023
• Revised: EN 45510-2-9:2008 - Guide for procurement of power station equipment - Part 2-9: Electrical equipment - Cabling systems
• Effective Date: 10-Jul-2018

Standards Content (Sample)

SLOVENSKI STANDARD
01-december-2020
Nadomešča:
SIST EN 62541-8:2015
Enotna arhitektura OPC - 8. del: Dostop do podatkov (IEC 62541-8:2020)
OPC Unified Architecture - Part 8: Data Access (IEC 62541-8:2020)
OPC Unified Architecture - Teil 8: Zugriff auf Automatisierungsdaten (IEC 62541-8:2020)
Architecture unifiée OPC - Partie 8: Accès aux données (IEC 62541-8:2020)
Ta slovenski standard je istoveten z: EN IEC 62541-8:2020
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 62541-8

NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2020
ICS 35.100.05; 25.040.40 Supersedes EN 62541-8:2015 and all of its amendments
and corrigenda (if any)
English Version
OPC Unified Architecture - Part 8: Data Access
(IEC 62541-8:2020)
Architecture unifiée OPC - Partie 8: Accès aux données OPC Unified Architecture - Teil 8: Zugriff auf
(IEC 62541-8:2020) Automatisierungsdaten
(IEC 62541-8:2020)
This European Standard was approved by CENELEC on 2020-07-27. 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.
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,
Turkey 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
© 2020 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 62541-8:2020 E

European foreword
The text of document 65E/708/FDIS, future edition 3 of IEC 62541-8, 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) 2021-04-27
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2023-07-27
document have to be withdrawn
This document supersedes EN 62541-8:2015 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 mandate given to CENELEC by the European Commission
and the European Free Trade Association.
Endorsement notice
The text of the International Standard IEC 62541-8:2020 was approved by CENELEC as a European
Standard without any modification.

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.cenelec.eu.
Publication Year Title EN/HD Year
IEC/TR 62541-1 - OPC unified architecture - Part 1: CLC/TR 62541-1 -
Overview and concepts
IEC 62541-3 - OPC Unified Architecture - Part 3: - -
Address Space Model
IEC 62541-4 - OPC Unified Architecture - Part 4: - -
Services
IEC 62541-5 - OPC Unified Architecture - Part 5: - -
Information Model
UNECE 20 - Codes for Units of Measure Used in - -
International Trade
IEC 62541-8 ®
Edition 3.0 2020-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
OPC unified architecture –
Part 8: Data access
Architecture unifiée OPC –
Partie 8: Accès aux données
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 25.040.40; 35.100.05 ISBN 978-2-8322-8464-3

– 2 – IEC 62541-8:2020 © IEC 2020
CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references . 7
3 Terms, definitions and abbreviated terms . 7
3.1 Terms and definitions . 7
3.2 Abbreviated terms . 8
4 Concepts . 8
5 Model . 9
5.1 General . 9
5.2 SemanticsChanged . 10
5.3 Variable Types . 10
5.3.1 DataItemType . 10
5.3.2 AnalogItem VariableTypes . 11
5.3.3 DiscreteItemType . 14
5.3.4 ArrayItemType . 17
5.4 Address Space model . 23
5.5 Attributes of DataItems . 24
5.6 DataTypes . 25
5.6.1 Overview . 25
5.6.2 Range . 25
5.6.3 EUInformation . 25
5.6.4 ComplexNumberType . 27
5.6.5 DoubleComplexNumberType . 27
5.6.6 AxisInformation . 28
5.6.7 AxisScaleEnumeration . 28
5.6.8 XVType . 29
6 Data Access specific usage of Services . 29
6.1 General . 29
6.2 PercentDeadband . 29
6.3 Data Access status codes . 30
6.3.1 Overview . 30
6.3.2 Operation level result codes . 30
6.3.3 LimitBits . 32
Annex A (informative) OPC COM DA to UA mapping . 33
A.1 Overview. 33
A.2 Security considerations . 33
A.3 COM UA wrapper for OPC DA Server . 33
A.3.1 Information Model mapping . 33
A.3.2 Data and error mapping . 37
A.3.3 Read data . 40
A.3.4 Write Data . 41
A.3.5 Subscriptions . 42
A.4 COM UA proxy for DA Client . 42
A.4.1 Guidelines . 42
A.4.2 Information Model and Address Space mapping . 42
A.4.3 Data and error mapping . 46

IEC 62541-8:2020 © IEC 2020 – 3 –
A.4.4 Read data . 48
A.4.5 Write data . 49
A.4.6 Subscriptions . 49

Figure 1 – OPC DataItems are linked to automation data . 9
Figure 2 – DataItem VariableType hierarchy . 10
Figure 3 – Graphical view of a YArrayItem . 19
Figure 4 – Representation of DataItems in the AddressSpace . 24
Figure A.1 – Sample OPC UA Information Model for OPC DA . 34
Figure A.2 – OPC COM DA to OPC UA data and error mapping . 38
Figure A.3 – Status Code mapping. 39
Figure A.4 – Sample OPC DA mapping of OPC UA Information Model and Address
Space . 43
Figure A.5 – OPC UA to OPC DA data & error mapping . 46
Figure A.6 – OPC UA Status Code to OPC DA quality mapping . 48

Table 1 – DataItemType definition . 11
Table 2 – BaseAnalogType definition . 12
Table 3 – AnalogItemType definition . 13
Table 4 – AnalogUnitType definition . 13
Table 5 – AnalogUnitRangeType definition . 14
Table 6 – DiscreteItemType definition . 14
Table 7 – TwoStateDiscreteType definition . 15
Table 8 – MultiStateDiscreteType definition . 15
Table 9 – MultiStateValueDiscreteType def
...