When operating an asset, certain requirements need to be fulfilled. This may include, that certain things need to be provided to the asset like pressure or electricity with a specific voltage and current. This may also include specific environmental conditions like a minimum and maximum temperature, air pressure and humidity and the weight and dimensions of the asset the environment need to support.
This specification does not define specific types of requirements. Other specifications, like IEC Common Data Dictionary or ECLASS do define those. This specification defines a standardized place to expose the requirements. It is recommended to use dictionary references, as defined in OPC 10000-19, to reference external dictionaries like IEC Common Data Dictionary or ECLASS to define the semantic of the specific requirements.
In order to provide access to the requirements, the concept of a Folder as defined in OPC 10000-5 is used. This specification just defines the use of the standardized BrowseName “Requirements” (defined in the Namespace of this specification). Servers might provide the requirements using different access paths, but they should provide the Requirements Folder as well. This Folder might be organized into other Folders, so Clients shall expect that they need to browse several hops to get to all requirements. In Figure 7, an example is given, also pointing with dictionary references to an external dictionary (ECLASS).
Figure 7 – Example providing Requirements