return to the IEC Standards

Note: The following is an excerpt from the official IEC catalog. It is provided here as a convenience and is not authoritative. Refer to the original document as the authoritative reference.

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.