Servers can expose UIElements providing user interfaces in the context of their FunctionalGroup container. Clients can load such a user interface and display it on the Client side. The hierarchy of FunctionalGroups represents the tree of user interface elements.
The UIElementType is abstract and is mainly used as filter when browsing a FunctionalGroup. Only subtypes can be used for instances. No concrete UIElements are defined in this specification. FDI (Field Device Integration, see IEC 62769) specifies two concrete subtypes
- UIDs (UI Descriptions), descriptive user interface elements, and
- UIPs (UI Plug-Ins), programmed user interface elements. The UIElementType is specified in Table 13.
Table 13 – UIElementType definition
Subtype of the BaseDataVariableType defined in OPC 10000-5.
The Value attribute of the UIElement contains the user interface element. Subtypes have to define the DataType (e.g. XmlElement or ByteString).