IEC 62541-6:2025

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