The right hand has to know what the left hand is doing, especially when they're working on top of each other, or close to it. In these lean-and-mean days, operations and performance knowledge needs to move faster than ever. As a result, this information must be allowed to be exchanged between plant floors and business levels despite the risks posed by computer viruses and unauthorized intruders. Here's how some experienced users and their networks are doing it.
Manufacturing Kogenate Factor VIII blood-clotting agent for hemophilia patients is serious and complicated business, so it demands some equally complex and well-coordinated networking. The biotech production process that Bayer Health Care uses to make it at its Berkeley, Calif., facility involves the usual two-stage method of growing cells in fermentation, and then purifying them to extract active ingredients. However, the specific process for building this coagulation drug is more complicated because it's difficult to assemble what is one of the world's largest complex-protein molecules. This complexity is essential for Kogenate to properly mimic in its patients the regular clotting factor found in people without hemophilia.
"When Kogenate Factor VIII was invented 20 years ago, it changed how this illness was managed," says David Kavanaugh, Bayer's principal process control system (PCS) engineer. "It enabled hemophilia to be treated with preventive therapy instead of having to be reactive."
The operational controls at Bayer's Kogenate production and related facilities include three primary systems located in multiple buildings at the site. The first monitors and controls flows, temperatures, levels, weights, dissolved oxygen and other variables in Bayer's fermentation vessels and related equipment using a variety of I/O modules and controllers managed by ABB's System 800xA distributed control system (DCS). There are about 8,000 I/O points spread among multiple fermenting units in Bayer's main production building.
The second system controls an advanced HVAC application that provides Bayer with a sterile manufacturing atmosphere for its cleanrooms. The motors, dampers, filters and other equipment are controlled by six building automation systems (BASs) from Siemens Industry, while their sensors and I/O components are controlled by Siemens' Apogee automation system.
The third system is Bayer's central utilities, which provide steam, ultra-pure water for injection (WFI) into the vessels, coolant, lights and power, and are monitored and controlled by GE Intelligent Platforms' Proficy iFix HMI/SCADA system. This system also includes several of Rees Scientific's Centron environmental monitoring systems (EMSs) for lab temperature monitoring.
Although each of the three systems worked well enough on its own island, Bayer's engineers and manager craved better data access, so they could make better and faster process decisions, and be more proactive and productive by throttling back downstream when an upstream problem occurs, or ramping up upstream when downstream indicates that it's idle and needs more to do.One for All, All for One
"It's always been part of our vision to make process data available to everyone that needs it, and to do it in a way that's easy to use," Kavanaugh says. "Previously, all three systems were standalone, each with their own PCs, HMIs and historians, and the only way to get information was to be physically in front of each one. So, our staff had to do a lot of running between buildings to get information that wasn't accessible otherwise and couldn't be shared. As a result, our main job for the past five years has been to tie these three systems together with an overall process control system. We began by creating a standalone fiberoptic and copper PCS network that reached all our buildings, and piggybacked it on top of the corporate IT infrastructure that already had fiber, switches and telecom running to all the buildings. However, we then installed our own dedicated Ethernet switches that were under our control, so we wouldn't disrupt corporate IT and they wouldn't disrupt us."
The PCS network uses TCP/IP communications via Cisco Systems Ethernet switches that enable intelligent data routing. On the plant floor, the 800xA DCS also converts data into a form the PCS above it can use and send up to the enterprise level.
To make the PCS network secure, Kavanaugh follows Bayer's existing corporate IT security standards, which include firewalls for physical access, passwords and other standard IT policies and procedures (Figure 1). "Our PCS network is physically separate from the corporate network, except for one connection through a firewall, which is Cisco's Adaptive Security Appliance switch."