Since its earliest days, the Open Process Automation Standard (O-PAS) has been paralleled and supported by a not-so-secret weapon—ExxonMobil’s proof-of-concept (PoC), prototype and testbed to evaluate its interoperability concepts and capabilities. These open process automation (OPA) projects contributed to the development of the standard, increased its credibility, and paved the way for other end-users to develop their own O-PAS projects. Now, ExxonMobil’s version is about to be deployed in a production setting, and prepare for eventual scale-up.
“We advocate open and standardized automation, and OPA is a great example. We’re executing our OPA lighthouse project in Baton Rouge this year, and advancing open-asset digital twins as the foundation for achieving speed and scalability from wherever,” explained Wade Maxwell, engineering VP at ExxonMobil Technology & Engineering Co., during the recent ARC Industry Forum in Orlando. “OPA is demonstrating its value in improved turnrounds, project planning and visual inspections. Openness and interoperability enable faster technology development and deployment at scale. This is an exciting time to be an engineer in our industry.”
Ryan Smeltzer, OPA program manager at ExxonMobil, added, “We talked for years about moving OPA from concept to reality, and now our lighthouse project will demonstrate OPA system compatibility, performance and support in 3Q24, as well as illustrate its value mechanisms, and provide key inputs into commercial scalability in our manufacturing facilities. We took a stepwise approach to developing OPA technology, standards and business models as we progressed from prototype to testbed to field deployment. The commercial deployment in Baton Rouge embodies the O-PAS architecture initially developed in 2016, and we’re implementing an OPA system with products built to O-PAS, Version 2.1, into our OPA lighthouse project.”
OPA implementation and scale-up
Following its earlier PoC and field tests, ExxonMobil’s OPA lighthouse project is presently progressing through its detailed engineering and staging phases with system integration provided by Yokogawa. The project has incorporated learnings from the initial PoC in 2017, prototype in 2020, and testbed since 2019. Smeltzer reported that OPA hardware fabrication and wiring are complete, and application testing is in progress.
“Factory acceptance testing (FAT) is expected to kick off in March and finish in April, and then it will be installed in the field and cutover. We plan to have this OPA system operational by 3Q24,” said Smeltzer. “We’re being very judicious about this demonstration project because we’re looking to prove to ourselves and the process industry that open, standards-based automation can be done at cost and the fleet level. We’re confident that we can land this field trial, and that it will be successful, so the next task is scaling up.”
Commercializing OPA via deployment starts with:
- Implementing OPA-based solutions to achieve near-term benefits;
- Engaging with suppliers to screen opportunities for using OPA via request for information (RFI) and requests for proposal (RFP);
- Focusing on software enablement via an app store-style outlet for delivering OPA solutions;
- Requiring OPA capabilities in purchased products; and
- Realizing the potential of UniversalAutomation.org (UAO) protocol based on IEC 61499 and industry-standard runtime.
“We always talked about having an app store structure for OPA, and now we can really prove it,” said Dave DeBari, OPA technical team leader at ExxonMobil and co-chair of OPAF’s application portability subcommittee. “Because our testbed includes an advanced computing platform (ACP) and remote I/O, we began working with Aimirim STI (https://en.aimirimsti.com.br) in February 2023 to help integrate advanced process controls (APC) within IEC 61499 at the function block level and test them in the testbed.”
Freedom for function blocks and algorithms
Though most O-PAS communications occur via OPC UA, DeBari explained that Aimirim also helped the testbed’s team to natively insert function blocks into UAO’s runtime and build-time functions, which enable it to use edge computing to perform advanced control tasks more effectively in the open process environment. For example, DeBari reported the testbed’s O-PAS communications framework (OCF) used Aimirim’s Opper model-predictive control (MPC) software with UAO runtime’s IEC 61499 capability for an APC demonstration on a simple, 2 x 2 feedforward control application. It was deployed in 4diac-RTE (FORTE), which is a small, portable C++ implementation of an IEC 61499 runtime environment that supports executing its function block (FB) networks on small, embedded devices. This demonstration yielded several exceptional results, including:
- Improved disturbance rejection in the feedforward application. On both increase and decrease pressure steps in the pressure-vacuum (PV) valve, where the regular PID function showed visible disturbances, Opper MPC anticipated this effect, leading to no visible effect on the PC valve.
- Faster unmeasured disturbance rejection. Oscillations present in steady-state for pressure and flow control were rejected by Opper MPC more quickly than the existing PID for both variables, leading to a considerable reduction in the standard deviation of the process variables. Standard deviation for pressure control was reduced from 2.23 with PID to 1.21 with Opper MPC, while standard deviation for flow control was reduced from 0.60 with PID to 0.55 with Opper MPC.
“Using edge computing for APC levels the playing field, and lets more startups use OPA, so they can bring more great algorithms and applications to market,” said DeBari. “Open process systems unlock value by decoupling and separating software from hardware to allow better real-time control and performance. This is technology we can set up and use today because it only takes 18 minutes to set up and fully commission a DCN in our testbed using orchestration script to safely deploy and run embedded control code. We never have to say ‘no’ to a project now because this kit can do it.”
DeBari added the original testbed in Woodlands, Texas, completed its R&D work in August-September 2023, and a 25% subset was moved in December to ExxonMobil’s campus in Spring, Texas. The remaining 75% went to Yokogawa’s facility in Sugar Land, Texas. Both can perform all of the testbed’s functions. Yokogawa reported it’s presently staging in preparation for the FAT to be conducted in 1Q24 for installation in the OPA lighthouse project in Baton Rouge to control a chemicals facility with about 2,000 I/O.
Smeltzer concluded, “We have tens of thousands of process PLCs in the field, and brownfield replacements and even greenfield projects are increasingly difficult, complex and costly with existing technology, so we needed to do a moonshot with OPA. It’s taken some collaboration, but OPA’s technical challenges were solvable, and it can provide definite economic advantages that will benefit everyone.”
