One huge potential benefit of the current push to new industrial communication standards, driven by the Industrial Internet of Things and Industry 4.0’s smart manufacturing initiatives, is open, secure, interoperable architectures that integrate solutions that address both discrete and process automation. These worlds of industrial automation and process control have largely been apart in the past but now, with the need to achieve much tighter integration with business systems and the supply chain, there is a new push for solutions that will enable a gradual merging of these two worlds based on common standards.
Process vs. Discrete Automation
For process automation companies, there are emerging possibilities for controls optimization by implementing a universal platform that covers both industrial automation and process automation using PC-based control.
New offerings from Beckhoff, for example, move in this direction by integrating process-specific protocols and interfaces, and by offering an extended range of products for hazardous areas including full implementation of HART functionality. By providing connectivity using process technology protocols such as HART, NAMUR, and FDT/DTM, and integrating these protocols and programming standards into its TwinCAT software development environment, this approach provides a familiar experience for users who previously worked with other software environments. The TwinCAT FDT (Field Device Tool) container can enable implementation of any field device drivers (Device Type Manager, DTM), so an entire HART configuration can be implemented efficiently using a single tool.
The system also provides a CommDTM for communicating with existing process control systems, as the DTMs can be implemented in any FDT container. This applies to all field devices connected to HART-capable EtherCAT Terminals. Devices can also be configured and parameterized remotely in known containers without requiring direct PLC access. OPC UA server and client functionality creates a method for secure global distribution of process data, as well as system control and remote maintenance capabilities.
The TwinCAT control and engineering platform now fully supports the HART protocol, and offers comprehensive libraries for process automation applications. Image source: Beckhoff
Role of OPC UA in Process Control
The transition of distributed control systems (DCS) to IIoT centric architectures will be driven by access and analysis of more data, along with seamless interoperability of multivendor components. As a result, the OPC Foundation has announced new initiatives to define an over-arching standard that incorporates the standards currently defined for communications interoperability (Foundation Fieldbus, HART, OPC, etc.) but also defines a reference and/or conformance platform that is standards-based, open, secure and interoperable. In the last year, OPC has been working with the Open Group’s Open Process Automation Forum to show why and how OPC UA can be applied to realize this vision.
The separation of the data model from its underlying technology architecture is a core strength of OPC UA. This separation is fundamental to adapting to new technologies including those defined for security and communication protocols. Even though underlying technologies may change, the integrity of the information model remains intact and applications typically do not need to be changed to implement new solutions.
A white paper on the OPC Foundation website provides insight into how this technology will be applicable to Brownfield applications. According to the paper, “In the near term, OPC Classic is likely to be more prevalent in brownfield sites for usage scenarios involving HMI, SCADA, and advanced applications. Although OPC UA provides a far richer feature set and is more flexible than OPC Classic, many of the concepts of existing OPC Classic specifications are maintained within OPC UA. This ensures that many features and concepts well-known to users of OPC Classic can be carried over to OPC UA.”