The following sections define the basic OPC UA Objects defined by MDIS. This includes Method definition as needed. The use cases / object interactions for each Object are defined in a separate section.
The MDISBaseObjectType is a base object that all other MDIS objects are constructed from. It is an abstract ObjectType and instances of it shall not exist. This Object will be used to create subtypes.
The MDISDiscreteInstrumentObjectType is a base type and can be subtyped or instances of it can be directly created. The Object can be used with multi-state type of data (stopped, moving, faulted). It could also be used for integer values from instruments. For a limit switch or on / off switch the MDISDigitalInstrumentObjectType should be used.
The MDISDiscreteOutObjectType is a subtype of MDISDiscreteInstrumentObjectType and can be subtyped or instance of it can be directly created. The Object can be used for Tristate or Multistate switches.
The MDISDigitalInstrumentObjectType is a base type and can be subtyped or instance of it can be directly created. The Object can be used to represent on / off type of functions.
The MDISDigitalOutObjectType is a subtype of MDISDigitalInstrumentObjectType and can be subtyped or instance of it can be directly created. The Object can be used for switching on / off types.
The MDISInstrumentObjectType is a base type and can be subtyped or instances of it can be directly created. The Object can be used for various types of analogues, e.g. pressure, temperatures, tank levels etc.
The MDISInstrumentOutObjectType is a subtype of MDISInstrumentObjectType and can be subtyped or instance of it can be directly created. The Object can be used for writing floating point values.
The MDISChokeObjectType object is a base type and can be subtyped or an instance of it can be directly created. A choke is a device that restricts the flow of a fluid (gases, liquids, fluidised solids, or slurries).
The MDISValveObjectType object is a base type and can be subtyped or an instance of it can be directly created. A valve is a device that directs or controls the flow of a fluid (gases, liquids, fluidised solids, or slurries). The MDISValveObjectType represents a two state valve type.
An abstract type that all aggregate ObjectTypes shall be derived from. This ObjectType allows Clients to easily identify aggregate Objects. For more information about aggregation see 9.5
The MDISTimeSyncObject (see 5.9.3) is a base ObjectType. An instance of this ObjectType shall be exposed as part of the MDISInformationObjectType, if the MDISTimeSyncObjectType is supported.
The MDISInformationObjectType (see 5.10) is a base ObjectType. An instance of this ObjectType shall be exposed under the Objects folder. It provides information about the MDIS Information model that is supported by the Server. It can also expose additional information related to MDIS.