Today OPC UA information models focused on the functional aspects of a dedicated device and the management of parameters in a device parameter set, are typically based on the OPC UA for Devices (DI) base information model (defined in [OPC 10000-100], referenced as OPC UA DI also in this document). In contradiction to this the I4.0 system modelling, including multiple aggregated devices and controllers, requires the representation of several different aspects of the system and therefore will lead to more sophisticated modelling approaches. Such a system model approach using four different independent partial models called “Facets”, linked together by typified references is shown in Figure 16. Here the Asset partial model contains an independent model related to orderable components (assets). The Physical Network partial model contains the independent model of the ethernet network structure. The PROFNET partial model contains all communication related aspects of the PN Controllers and Devices in the system. The Function partial model at least represents the application function aspect of the system. Objects out of the different partial models are connected to each other by typified references expressing semantic information about their relationship.
To be future proof and easily integrable to different base modelling approaches, this Companion Specification defines the PROFINET information model as an independent partial model using the OPC UA Interface and AddIn technology (See [OPC 10001-7]) . This gives the opportunity to connect the same unique PROFINET base information model to the OPC UA DI base model and to use the same PROFNET base model as partial model for the PROFINET communication aspect in the “Facet” modelling approach as shown in Figure 16.
Figure 16 – “Facet” modelling approach for I4.0 System Modelling
The base information model in chapter 6.3 defines all common types of the PROFINET OPC UA information model.
The Annex B shows how to use the base information model together with OPC UA for Devices.
|DCP||The mentioned values or properties are read with the DCP Identify service|
|GSDML||The mentioned values or properties are read from a GSD file|
|Read||The mentioned values or properties are read with a CLRPC or RSI read record service|
|The mentioned values are obtained by the blocks (optionally also subblocks) and fields given in the description. The following syntax is used: “Block||field”.|