prEN IEC 62541-8:2024

SLOVENSKI STANDARD
01-marec-2024
Enotna arhitektura OPC - 8. del: Dostop do podatkov
OPC Unified Architecture - Part 8: Data Access
OPC Unified Architecture - Teil 8: Zugriff auf Automatisierungsdaten
Architecture unifiée OPC - Partie 8: Accès aux données
Ta slovenski standard je istoveten z: prEN IEC 62541-8:2024
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.

65E/1055/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 62541-8 ED4
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2024-01-26 2024-04-19
SUPERSEDES DOCUMENTS:
65E/980/RR
IEC SC 65E : DEVICES AND INTEGRATION IN ENTERPRISE SYSTEMS
SECRETARIAT: SECRETARY:
United States of America Mr Donald (Bob) Lattimer
OF INTEREST TO THE FOLLOWING COMMITTEES: PROPOSED HORIZONTAL STANDARD:

Other TC/SCs are requested to indicate their interest, if any, in
this CDV to the secretary.
FUNCTIONS CONCERNED:
EMC ENVIRONMENT QUALITY ASSURANCE SAFETY
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CENELEC, is drawn to the fact that this Committee Draft for
Vote (CDV) is submitted for parallel voting.
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to be included should this proposal proceed. Recipients are reminded that the CDV stage is the final stage for submitting ISC
clauses. (SEE AC/22/2007 OR NEW GUIDANCE DOC).

TITLE:
OPC Unified Architecture - Part 8: Data Access

PROPOSED STABILITY DATE: 2026
NOTE FROM TC/SC OFFICERS:
electronic file, to make a copy and to print out the content for the sole purpose of preparing National Committee positions.
You may not copy or "mirror" the file or printed version of the document, or any part of it, for any other purpose without
permission in writing from IEC.

IEC CDV 62541-8 © IEC 2023
1 CONTENTS
3 FOREWORD . vii
4 1 Scope . 1
5 2 Normative references . 1
6 3 Terms, definitions and abbreviated terms . 1
7 3.1 Terms and definitions . 1
8 3.2 Abbreviated terms . 2
9 4 Concepts . 2
10 5 Model . 4
11 5.1 General . 4
12 5.2 SemanticsChanged . 4
13 5.3 Variable Types . 4
14 5.3.1 DataItemType . 4
15 5.3.2 AnalogItem VariableTypes . 5
16 5.3.3 DiscreteItemType . 8
17 5.3.4 ArrayItemType . 10
18 5.4 Address Space model . 15
19 5.5 Attributes of DataItems . 16
20 5.6 DataTypes . 17
21 5.6.1 Overview . 17
22 5.6.2 Range . 17
23 5.6.3 EUInformation . 17
24 5.6.4 ComplexNumberType . 19
25 5.6.5 DoubleComplexNumberType . 20
26 5.6.6 AxisInformation . 20
27 5.6.7 AxisScaleEnumeration . 21
28 5.6.8 XVType . 21
29 6 Quantities and Units model . 23
30 6.1 General . 23
31 6.2 Quantities entry point . 23
32 6.3 Syntax References . 23
33 6.3.1 General . 23
34 6.3.2 Using Dictionary References . 24
35 6.3.3 Syntax Reference Identifier . 25
36 6.4 ObjectTypes . 27
37 6.4.1 QuantityType ObjectType definition . 27
38 6.4.2 UnitType and subtypes . 28
39 6.4.3 SyntaxReferenceEntryType ObjectType definition . 31
40 6.5 References . 32
41 6.5.1 HasEngineeringUnitDetails. 32
42 6.5.2 HasQuantity . 32
43 6.6 DataTypes . 32
44 6.6.1 AnnotationDataType DataType definition . 32
45 6.6.2 LinearConversionDataType DataType definition . 33
46 6.6.3 ConversionLimitEnum . 34
47 6.6.4 QuantityDimension . 34
48 7 Data Access specific usage of Services . 37

iii IEC CDV 62541-8 © IEC 2023
49 7.1 General . 37
50 7.2 PercentDeadband. 37
51 7.3 Data Access status codes . 37
52 7.3.1 Overview . 37
53 7.3.2 Operation level result codes . 37
54 7.3.3 LimitBits . 39
55 Annex A (normative) OPC COM DA to UA mapping . 40
56 A.1 Introduction . 40
57 A.2 Security Considerations . 40
58 A.3 COM UA wrapper for OPC DA Server . 40
59 A.3.1 Information Model mapping . 40
60 A.3.2 Data and error mapping . 44
61 A.3.3 Read data . 47
62 A.3.4 Write Data . 48
63 A.3.5 Subscriptions . 48
64 A.4 COM UA proxy for DA Client . 49
65 A.4.1 Guidelines . 49
66 A.4.2 Information Model and Address Space mapping . 49
67 A.4.3 Data and error mapping . 53
68 A.4.4 Read data . 55
69 A.4.5 Write data . 56
70 A.4.6 Subscriptions . 56
71 Annex B (normative) UCUM Symbols . 58
72 B.1 Introduction - License . 58
73 B.2 Representation . 58
74 B.3 Tables of Terminal Symbols . 59
75 B.1.1 Prefixes . 59
76 B.1.2 Base Units . 60
77 B.1.3 Derived Unit Atoms . 60
78 B.1.4 Customary Unit Atoms . 62
79 B.1.5 Other Legacy Units . 65
80 Annex C (informative) Outline of Syntax References . 69
81 C.1 UCUM Syntax Reference . 69
82 C.2 QUDT Syntax Reference . 69
83 C.3 UNECE Syntax Reference . 70
84 C.4 IEC CDD Syntax Reference . 70
85 C.5 LATEX_SIUNITX Syntax Reference . 71
IEC CDV 62541-8 © IEC 2023 iv
87 FIGURES
89 Figure 1 – OPC DataItems are linked to automation data . 3
90 Figure 2 – DataItem VariableType hierarchy . 4
91 Figure 3 – Graphical view of a YArrayItem . 12
92 Figure 4 – Representation of DataItems in the AddressSpace . 16
93 Figure 5 – Enhanced EUInformation example . 18
94 Figure 6 – Quantity model overview . 23
95 Figure 7 – References to external works . 25
96 Figure 8 - QuantityType . 27
97 Figure 9 - Units model . 28
98 Figure A.1 – Sample OPC UA Information Model for OPC DA . 41
99 Figure A.2 – OPC COM DA to OPC UA data and error mapping . 45
100 Figure A.3 – Status Code mapping . 46
101 Figure A.4 – Sample OPC DA mapping of OPC UA Information Model and Addre
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