The PI and OPC Foundation Joint Working Group is making good progress in the preparation of an OPC UA Companion Specification for PROFINET. This team was launched following the discussions and prioritization of issues relevant to PI (PROFIBUS & PROFINET International) in the “Industrie4.0@PI” working group in May 2017. The use cases Asset Management and Diagnosis emerged as especially important.
The collaboration of PROFINET and OPC experts from different firms currently concentrates on detailed elaboration of concrete use cases, because only a clear, common understanding of users’ requirements leads to an appropriate and subsequently implemented specification.
The PROFINET specification has already performed a lot of preparatory work on Asset Management and Diagnosis use cases, which were also rated as especially relevant by the users. The scope and level of detail of these functions are unique. Thus, the required information is provided to the user in accordance with a standardized structure in the OPC UA object tree following mapping of the objects in the OPC UA Information Model made available via the PROFINET system during vertical access by an IT system via OPC UA client-server calls. This information can then be easily processed in superimposed systems.
Thanks to the TCP/IP channel in PROFINET networks, which has always been open, OPC UA access can take place via the controllers, gateways, or even directly with subordinate devices. Therefore a start in OPC UA can take place flexibly and in phases.
OPC UA is not a new topic for PI. Thus, the FDI specification energetically pursued by PI uses OPC UA services. The already applied OPC UA specification for devices is also used in the PROFINET mapping. The coordination with new activities for mapping of IO-Link in accordance with OPC-UA takes place continuously, ensuring seamless joint integration into the OPC UA Object Model.
The activities aim to create an OPC UA PROFINET Companion Specification by mid-2019. The device manufacturers can continue to integrate the proven PROFINET services without change. A display of information using OPC UA services in accordance with currently defined mapping can then take place in the corresponding devices in accordance with customer requirements.