At ABB Automation & Power World 2012 this week in Houston, ABB has its System 800xA control system on display in the Technology & Solutions Center, showing how the platform can provide an evolutionary upgrade path that preserves legacy control system investments.
During a session this afternoon, conference attendees got the opportunity to hear one customer's account of how his plant has been able to evolve its control system with System 800xA, leaving in place its legacy INFI 90 systems while updating operator stations, controllers and power supplies.
BASF's site in Windsor, Ontario, which makes automotive paints, has been around for more than 100 years. It became part of chemical giant BASF through the Inmont acquisition in the early 1980s.
In 1994, the plant installed its first distributed control system (DCS), an INFI 90 from ABB, including Conductor VMS redundant servers and Conductor VMS clients. By 2004, the plant was facing issues and had to figure out how it was going to support an aging system, said Jiri Prochazka, instrument and electrical engineer, who faced the challenge of increasing productivity and overall equipment effectiveness (OEE). "Instead of ripping it out, we decided to preserve the installed base," he said. "So we developed an evolution plan with ABB."
The team began by upgrading the engineering tools and then moved on to the front-end control stations, controllers and power supplies. In June 2007, BASF installed new operator stations. ABB had standardized on the 800xA platform, Prochazka said, "So we decided to go ahead and upgrade our VMS stations."
Because BASF's operations are manually intensive, the plant does not have a classic control room, but rather has operator stations sitting on the plant floor, Prochazka said. "We had to come up with a solution to install clients on the floor in a classified environment."
They ran the systems in parallel for a couple months to make sure everything would work correctly, then disconnected the VMS units. As it turns out, it was just in time, with problems cropping up on the VMS systems. "We could probably find the hardware to replace the VMS systems, but the problem was to find the people who still remember how to work with VMS code," Prochazka added.
In 2009, BASF decided to expand its Windsor facility to include refinishing products. The existing system had about 2000 I/O points for process automation of blending, mixing, batch processes and dispersions, and the new line would add about 600 more.
BASF needed the operators to seamlessly control the new refinishing products line while operating the existing blending, mixing, batch processes and dispersion lines. The field wiring would remain unchanged, so the INFI 90 needed to interface with the System 800xA.
ABB's solution was to use a Harmony PCU Gateway (HPG) to connect the existing BRC400s to the new refinishing line's AC800M controllers. The HPG 800 was designed to provide robust, peer-to-peer communications with the AC800M controllers via CI867 Modbus TCP CEX modules. "We're actually controlling across that HPG a lot," said Jim Luffman, project manager for ABB in Burlington, Ontario. "We expected about 200 links, but ended up with around 1000."
The operators have seamless control of the new refinishing line with the addition of some new graphics, Luffman said. "The operator can't tell which controller he's using," he added. "Whether it's the new or old system, it's transparent to the operator."
Working in a Class 1, Zone 1 environment, BASF had limited real estate to add the new refinishing line. ABB's solution added S800 I/O modules with embedded intrinsic safety, creating a total of six I/O cabinets distributed throughout the process areas with a minimized footprint.
"Our site continues to evolve," said Prochazka, noting that the next steps earmarked in the process are to replace obsolete PLCs to AC800M controllers and S800 input and output cards, eliminating control islands.
"I think we have made the right decision to protect the installed base," he said. "We did not rip and throw away the existing infrastructure. In the end, we finished and completed the migration process and ended up with an up-to-date, state-of-the-art DCS."