UML class diagram - Metadata information model

"Metadata is "data about data". The term is ambiguous, as it is used for two fundamentally different concepts (types). Structural metadata is about the design and specification of data structures and is more properly called "data about the containers of data"; descriptive metadata, on the other hand, is about individual instances of application data, the data content.
Metadata are traditionally found in the card catalogs of libraries. As information has become increasingly digital, metadata are also used to describe digital data using metadata standards specific to a particular discipline. By describing the contents and context of data files, the quality of the original data/ files is greatly increased. For example, a webpage may include metadata specifying what language it is written in, what tools were used to create it, and where to go for more on the subject, allowing browsers to automatically improve the experience of users." [Metadata. Wikipedia]
The UML class diagram example "Metadata information model" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Rapid UML solution from the Software Development area of ConceptDraw Solution Park.

"RT-middleware (Robotics Technology Middleware) is a common platform standards for Robots based on the distributed object technology. RT-middleware supports the construction of various networked robotic systems by the integration of various network enabled robotic elements called RT-Components. The specification standard of the RT-component is discussed / defined by the Object Management Group (OMG). ...
In the RT-middleware, robotics elements, such as actuators, are regarded as RT-components, and the whole robotic system is constructed by connecting those RT-components. This distributed architecture helps developers to re-use the robotic elements, and boosts the reliability of the robotic system.
Each RT-component has port as an endpoint for communicating other RT-components. Every port has its type and the ports which have the same type can be connected each other.
RT-components also has its state, so the RT-components behaves as state machines. The states that RT-components can have are CREATED, INACTIVE, ACTIVE, and ERROR, and the states and behaviors are controlled by the execution-context. If developers want to change the behavior of their RT-components, the execution-context can be replaced at run-time." [RT middleware. Wikipedia]
The UML state machine diagram example "State transitions of RT-component" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Rapid UML solution from the Software Development area of ConceptDraw Solution Park.