Wouldn't it be nice if distributed control systems (DCS) could be migrated to new solutions during a nice leisurely shutdown? It sure would, but this dreamlike scenario almost never happens, so most real-world migrations are rife with complex switchover and integration tasks, harried schedules, not to mention disorganization and stress.
To buck this difficult tradition, Givaudan recently collaborated with Automated Control Concepts, Inc. (ACC) to replace the DCS and other components at its food flavorings plant in East Hanover, N.J., and accomplish this typically difficult project seamlessly over several weekends in 2014. ACC is a Rockwell Automation Solution Partner.
"The old DCS at the East Hanover facility was having a lot of failures, and the staff was buying parts on eBay, so it was really time to replace it," said Chris Alexander, process control engineer, Givaudan.
[sidebar id =1]"Gauvidan's staff wanted the new control system to work the same as the old one, maintain existing points, and reuse field wiring and field devices," added Arlene Weichert, vice president of sales, ACC. "However, they also needed the migration to be done with no downtime or loss of production, so we had to do it during a few weekends during the summer."
New flavor infrastructure
Alexander reported that the plant's new control system and network consists of four primary process areas with 3,800 I/O points. These areas include large and small distillation areas, flavor concentration and conical extraction, mix tanks and blend tanks, dedicated vanilla extraction equipment, and a roaster/dryer application for vanilla with highly automated sequences.
"Gauvidan is the world's largest manufacturer of vanilla flavorings and all-natural ingredients," explained Weichert. "This is another reason why the DCS migration couldn't cause any shutdowns or lost production because many of Gauvidan's products go to other plants, and so those plants rely on the East Hanover plant."
To serve these applications, Gauvidan's new control system and network included five PlantPAx controllers, HMI software, historian software and a web-based manufacturing business intelligence solution. The application's Windows-based server environment also uses VMware components. In addition, several I/O panels were reused by combining existing enclosures with newly fabricated subpanels using Flex I/O modules. The plant's new displays included three thin clients repurposed from existing workstations, an ACP ThinManager terminal server, another thin client for vanilla processing, and an engineering workstation.
All of these devices are linked via a redundant, multi-mode fiber optic network, which includes two main Stratix switches, and a parallel device-level ring network for motor control centers (MCC) and solenoid panels.
"It was great to gain this redundancy because if any device was unplugged or dropped out, then the rest of the network and other devices could keep running," added Alexander. "Plus, we can also monitor the network for any breaks."
As for the switch from multicolor to grayscale in the new system's HMI display, Alexander added, "People asked where the color went, but when we showed them that they didn't need to program in code anymore and could just check boxes, it helped a lot," he added. "In addition, the new control system lets us track and trace operating behaviors, and find out reasons for burnt batches or poor-quality raw materials."
Weichert added that the migration was carried out in a series of five short cutovers during the available long weekends. "We installed and tested the Ethernet network before cutovers," she said. "Testing of each instrument was long before cutover to create a list of faulty instruments. Repair and replacement of faulty of instruments was done before cutover where possible, and we also did operator and technician training before cutovers.
"Each one of the five cutovers included about 400-800 I/O points. Operations even left raw material in some equipment and tanks, but we were able to cut over and add the new panels, and then finish the same batch with the new equipment. Finally, all of the required cutovers were finished ahead of schedule."
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