6 Surface Technology General Types Information Model overview

This companion specification is intended to be the basis for several companion specifications in the field of surface technology. Different ObjectTypes have been developed for surface technology such as the

  • STSysType (represents a machine or system)
  • STCompType (represents a component of a machine or system)
  • STBaseControllerType (represents a process control)
  • STJobManagementType (represents a higher level system that is managing the production process).

Figure 6 shows an overview of how the different ObjectTypes can be hierarchically arranged in an information model.

NOTE:The range of functions of the modelled ObjectTypes is broader than that shown here, which only illustrates the relationships between the different ObjectTypes.

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Figure 6 – Information Model overview

The STSysType, which is represented by the green Nodes in Figure 6, can be used to model more complex plants and systems. In some cases, these systems can contain different components. The STCompType was developed to map these in detail. Instances of components must be located within the Components Object of the corresponding system. In the example shown, MyComponent (these are the blue Nodes) represents such an exemplary component of the system MySystem1.

The STBaseControllerType, which is illustrated by the purple nodes, represents a controller that can control one or more systems. The controller represents a logical unit of a physical machine. It has the simple functionalities of startup and shutdown of the systems. In addition, system specific functionalities can be developed in a companion specification or by the end user.

The STJobManagementType is represented by the yellow nodes in Figure 6. Work orders, which usually come from higher-level systems, often do not know the exact recipe of a production process. The STJobManagementType modelled in this companion specification has been extended to include alias handling functionality (OPC 10000-17). This allows the user to provide programs within the controller with an alias, which can then be executed directly by the STJobManagementType. This allows the STJobManagementType to control the STBaseControllerType. It is also possible to link the alias directly with the Setpoint of a ProcessValueType. The STJobManagementType therefore has the ability to control the entire production process.