Significant changes are brewing in the way automation systems are designed and integrated. February’s annual ARC Forum, which devoted several sessions to open process automation, provided a glimpse of what’s happening. The sizable audiences at these sessions testified to the increasing interest in developments.
Today’s process control systems pose numerous challenges to operating companies. For example, their closed proprietary interfaces make integrating products from different vendors difficult and costly. Indeed, they may bind a plant to its incumbent supplier, thus limiting options. In addition, many installed systems were designed before cybersecurity emerged as an important issue.
Standards-based open systems provide a way to avoid these difficulties, say the two groups spearheading such efforts: NAMUR, the User Association of Automation Technology in Process Industries, Leverkusen, Germany, which counts more than 160 operating companies worldwide as members; and the Open Process Automation Forum (OPAF), Austin, Texas, which has over 90 members around the globe, including operating companies and automation vendors. Both stress that their efforts are complementary rather than competitive. And both recently reported significant progress.
The NAMUR Open Architecture concept focuses mainly on the interface for communicating with the process control system rather than changes in the process control system itself.
A key element of that approach, the Module Type Package, provides a standard, vendor-independent description of aspects of automation that eases integration of process units. It can handle not only components in modular production but also package units in conventional plants.
Indeed, the first application of MTP in an industrial environment involved integration of a chiller package at an Evonik plant in Singapore. The skid has a programmable logic controller from Siemens while the plant uses a Yokogawa distributed control system. The chiller was started up in June 2019; errorless data transfer took place immediately after physically connecting the systems. This issue’s article “Plant Pioneers Use of Automation Concept,” provides more details.
Meanwhile, OPAF’s core mission is to construct a “standard of standards” for open, interoperable, secure process automation. Such a framework will allow industry to better leverage new digital tools like artificial intelligence and edge computing while also enabling affordable in-situ equipment upgrades, rapid reconfiguring of production and other important benefits, the group stresses.
Its Open Process Automation Standard (O-PAS) features an alternative architecture that flattens the conventional pyramidal structure, eliminating its hierarchical nature. OPAF also is working to establish business practices and procedures for the new open environment. In addition, it is tackling conformance/certification of products.
O-PAS Version 1, released in 2019, defines the communication (OPC UA) security and services necessary to ensure interoperability. O-PAS Version 2, issued in February, adds standard information models for digital control nodes, signals, alarms, etc., and begins to address portability of configurations and applications. O-PAS Version 3, expected in late 2021, will include system orchestration, conformance and certification.
Already, ExxonMobil and BASF are operating “test beds” to assess and refine O-PAS-compliant technologies from multiple vendors.
NAMUR and OPAF are cooperating to develop a harmonized vision of the role of MTP and O-PAS, combining an industrial data standard with open industrial control systems.
We will continue to follow these developments and plan to publish an article on O-PAS in the near future.