IEC 62541-6:2025

IEC 62541-6:2025

December 2025
International standard Current

OPC unified architecture - Part 6: Mappings

IEC 62541-6:2025 specifies the mapping between the security model described in IEC 62541‑2, the abstract service definitions specified in IEC 62541‑4, the data structures defined in IEC 62541‑5 and the physical network protocols that can be used to implement the OPC UA specification.This fourth edition cancels and replaces the third edition published in 2020. This edition constitutes a technical revision.This edition includes the following significant technical changes with respect to the previous edition:a) addition of support for ECC to UA Secure Conversation;b) use of the AuthorityKeyIdentifier extension in Certificate Revocation Lists;c) enhancement of JSON mapping of Unions;d) addition of Decimal data type encoding.e) description of ECC keyUsage rules;f) addition of Media assigned by IANA to UANodeSet definition;g) addition of requirements for user and issuer Certificates;h) addition of rules which specify what happens when DateTime precision is lost;i) addition of rules to allow for the truncation of strings containing embedded nulls.J) definition of a normative string representation for NodeId, ExpandedNodeId and QualifiedName for JSON mapping.k) requirement that TAI times be converted to UTC;l) new possibility to omit Symbol if unknown in JSON encoding;m) addition of fields needed to support RolePermissions to the UANodeSet

Main informations

Collections

International IEC standards

Publication date

December 2025

Number of pages

138 p.

Reference

IEC 62541-6:2025

ICS Codes

25.040.40   Industrial process measurement and control
35.100.05   Multilayer applications

Print number

1
Sumary
OPC unified architecture - Part 6: Mappings

IEC 62541-6:2025 specifies the mapping between the security model described in IEC 62541‑2, the abstract service definitions specified in IEC 62541‑4, the data structures defined in IEC 62541‑5 and the physical network protocols that can be used to implement the OPC UA specification.
This fourth edition cancels and replaces the third edition published in 2020. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) addition of support for ECC to UA Secure Conversation;
b) use of the AuthorityKeyIdentifier extension in Certificate Revocation Lists;
c) enhancement of JSON mapping of Unions;
d) addition of Decimal data type encoding.
e) description of ECC keyUsage rules;
f) addition of Media assigned by IANA to UANodeSet definition;
g) addition of requirements for user and issuer Certificates;
h) addition of rules which specify what happens when DateTime precision is lost;
i) addition of rules to allow for the truncation of strings containing embedded nulls.
J) definition of a normative string representation for NodeId, ExpandedNodeId and QualifiedName for JSON mapping.
k) requirement that TAI times be converted to UTC;
l) new possibility to omit Symbol if unknown in JSON encoding;
m) addition of fields needed to support RolePermissions to the UANodeSet
Replaced standards (1)
IEC 62541-6:2020
July 2020
International standard Cancelled
OPC Unified Architecture - Part 6: Mappings

IEC 62541-6:2020 specifies the OPC Unified Architecture (OPC UA) mapping between the security model described in IEC TR 62541-2, the abstract service definitions specified in IEC 62541-4, the data structures defined in IEC 62541-5 and the physical network protocols that can be used to implement the OPC UA specification. 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) Encodings: • added JSON encoding for PubSub (non-reversible); • added JSON encoding for Client/Server (reversible); • added support for optional fields in structures; • added support for Unions. b) Transport mappings: • added WebSocket secure connection – WSS; • added support for reverse connectivity; • added support for session-less service invocation in HTTPS. c) Deprecated Transport (missing support on most platforms): • SOAP/HTTP with WS-SecureConversation (all encodings). d) Added mapping for JSON Web Token. e) Added support for Unions to NodeSet Schema. f) Added batch operations to add/delete nodes to/from NodeSet Schema. g) Added support for multi-dimensional arrays outside of Variants. h) Added binary representation for Decimal data types. i) Added mapping for an OAuth2 Authorization Framework.

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