Vertical Communication with PROFINET
Enable the Digital Transformation
For the future of automation, a significant increase in productivity is required. The most promising candidate for this is the digital transformation. An enabling factor is the need for huge amounts of data out of the field level of production. These data are still existing today, trapped on thousands of field devices. But the access and conditioning of the data at the borderline between OT and IT in today’s production sites acts like a data barrier.
Semantic Interoperability and Device Integration
To overcome these problems, PI has extended its portfolio with new technologies and standards for vertical communication. Importantly, field level data which must be processed at the IT level needs to be provided in an IT-conformant way. This means it should be object oriented and as part of an information model (IM). Therefore, PI contributed its Part 30140 PROFINET Companion Specification series to the well-established OPC UA ecosystem which provide:
- Semantic interoperability by standardized IMs
- Device Integration (DI) for PROFINET Profile devices
- DI for vendor-specific functionality and IMs
Standardized IMs are provided by the OPC UA Parts 30140 to 30143 and 30145 for PROFINET, energy management, remote I/O, encoders and drives. DI for vertical communication via edge devices is supported by IMs matched to existing PROFINET Profiles. The OPC UA Part 30144 specification enables DI for vendor-specific device functionality by data and IM information available out of the PROFINET GSD file.
Benefits for Plant Operators and Device Manufacturers
Standardized information models offer multiple benefits for plant operators. They make it easy to search for specific aspects in the IMs of different machines and devices. Also it is easy to sum up variables from different devices because the calculation base is standardized cross-device. At least costs for client applications can be cut down because standard interfaces can be used instead of custom specific implementations.
But also device and machine manufacturers benefit from a standardized IM because they can focus on one standard implementation instead of supporting multiple custom specific implementations or to supersede a vendor-specific development.
PI Companion Specifications are Combinable
PI introduced the new Facet Modelling Technology and dedicated its Companion Specifications to this modern concept. Compared to the Part 100 DI modelling approach, Facet Modelling allows the combination of partial models out of different Companion Specifications into a comprehensive IM. This is quite important if devices support multiple aspects e.g. like a drive which supports a drive axis functionality together with energy management aspects. Also, Facet Modelling makes it easy to use a unique submodel for the same aspect for different device types.
Conclusion
Promises made by Industry 4.0 for flexible access to all data in production are still strongly requested by plant operators today. Initial approaches based on converged networks are still not available today and will not fit into brownfield scenarios. More realistic is a step by step approach by adding vertical communication to the existing Industry 3.0 pyramid. PI supports this IT/OT integration with its OPC UA 30140 Companion Specification series, helping to reduce the cost barrier and thereby pushing this technology.
Dr. Andreas Uhl
WG Lead OPC UA Integration
