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