ISO/IEC 14476-4:2010 provides a specification of QoS management for accomplishing desirable QoS for a duplex multicast transport connection. For this purpose, it describes the QoS management operations in duplex multicast transport connection such as QoS negotiation, QoS monitoring and QoS maintenance. 

IEC 61158-6-24:2014 defines the protocol provided to define the wire-representation of the service primitives defined in IEC 61158-5-24, and define the externally visible behaviour associated with their transfer. This standard specifies the protocol of the Type 24 fieldbus Application Layer, in conformance with the OSI Basic Reference Model (ISO/IEC 7498-1) and the OSI application layer structure (ISO/IEC 9545).

IEC TR 62541-1:2016(E) is a Technical Report and presents the concepts and overview of the OPC Unified Architecture (OPC UA). Reading this document is helpful to understand the remaining parts of this multi-part document set. 

IEC 62541-5.2015 defines the Information Model of the OPC Unified Architecture. The Information Model describes standardised Nodes of a Server's AddressSpace. These Nodes are standardised types as well as standardised instances used for diagnostics or as entry points to server-specific Nodes.