A spoonful of industrial computers

CONTROL's contributing editor Wayne Labs notes that while that well-known spoonful of sugar may work for sick kids, manufacturers may need a dose of industrial computing to cure ailments in their processes.

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By Wayne Labs, Contributing Editor

FOUNDED in 1972 and employing more than 100 people, Vector Corporation of Marion, Iowa, manufactures production equipment for processing solid dosage/form materials for the pharmaceutical, health care, chemical, food, confectionery and pyrotechnics industries. Included in the product lines are tablet coating machines, fluid bed granulator/coater/dryers, high shear granulators, roller compactors, tablet presses and automated process control systems. Primary distribution markets are North and South America and Europe, with an increasing emphasis on other continents, making Vector a global company.

Batch Systems Control the Process
There are two types of tablet coating systems: continuous and batch. Though not the company’s standard product line, continuous coating systems typically produce very large volumes per run and use shorter coating times per volume. Typical applications for continuous coaters include OTC medicines and vitamin products. Batch systems are usually employed for all prescription products, and can also be used for OTC products and vitamins. Batch systems generally provide better control of coating quality, uniformity and efficiency. They also provide batch documentation, allow process development and scale-up, and have minimal product loss.

Vector’s batch-based tablet coating systems include a standalone coating machine, plus several peripherals (such as driers and filters) to supply correct amounts of air at the right temperature, humidity and pressure. Available in varying capacities, these systems use a Windows XP Professional-based host computer to supervise every step of each batch process, which includes monitoring up to 200 I/O points every 10 seconds. For most pharma applications, FDA regulations require a clean-in-place (CIP) skid. To meet U.S. Food and Drug Administration (FDA) 21 CFR Part 11 electronic recordkeeping rules, the Compu 4, ISA S-88 based control system uses both custom batch software and off-the-shelf SCADA software, and is considered a 21 CFR Part 11 “Closed System.” A closed system is defined as “an environment in which system access is controlled by persons who are responsible for the content of electronic records that are on the system.” This includes not only batch records but also the underlying Windows XP Professional operating system.

While a small PLC, such as the Rockwell SLC 5/05 Series, is used to control the coating machine’s speed, air flow, temperature, humidity, pressure and other process variables, an industrial computer supervises the PLC, associated peripheral systems, and the CIP system.

MEETING 21 CFR PART 11 SPECS
    

Vector’s Model VPC1355 batch tablet coater uses a 21-in. NEMA 4X CCS industrial computer with a RAID 1 hard disk system.

According to Wanda Earll, Vector’s controls technician, “In the past, the company used Dell desktop PCs and packaged them in NEMA 4X enclosures, but with most applications today, space is at a premium, and a smaller computer with an integrated display saves space.” In addition, “An industrial computer with a NEMA 4X sealed, stainless steel faceplate simplifies packaging the system to NEMA 4X specs, eliminating separate enclosures to house unprotected desktop computers and separate displays,” notes Earll.

Consequently, Vector began seeking an industrial computer/display, preferably with a depth of less than 9 in. This industrial computer needed to communicate via Ethernet to the PLC over one port and to the user’s plant-wide Ethernet on another port. Other requirements included a 21-in. flat panel display and an industrial, sealed keyboard. The importance of the large screen could not be minimized. Earll noted that many users tend to work at a distance and often off axis, so large type and a wide viewing angle are important application requirements.

Special Computer Requirements
While the FDA regulations impose several security regulations on a computer system, the safety and longevity of the data is just as important. When the FDA requires it, pharma and food producers must be able to call up historical data at a moment’s notice for tracking and tracing purposes. “Disaster recovery is crucial in the pharma industry,” according to Tim Beauchamp, Vector’s controls engineer.
"To protect the system’s acquired data, a RAID 1 hard disk array was specified as the primary storage system for the host computer.” RAID 1 arrays use two hard disks in a mirror configuration. If one disk fails, the same data can be found on the other hard disk.

Finding an industrial computer that could be housed with the display in a pendant arm enclosure from Strongarm was an important space-saving consideration for Vector. Because tablet-coating operations require a system washdown after every day, product change or shift, Vector specified NEMA 4X-rated computers and enclosures.

Tablet-coating operations typically use either aqueous coatings or solvent-based coatings (typically acetone or isopropyl alcohol—both very volatile). While aqueous coatings present no difficulty in packaging beyond NEMA 4X, packaging a computer/display system for solvent-based coatings typically requires an intrinsically safe enclosure rated Class 1, Div. 1 or 2. In Europe, Class 1 Div. 1 is equivalent to ATEX Zone 1. This means that the computing equipment must withstand initial purge pressures and operate continuously under pressure.

Finding an Industrial Computer
After investigating several industrial computer manufacturers and their products, Vector settled on CCS-Industrial’s 21.3 in., Model ICP2100 panel PC. The computer has a NEMA 4X-rated, stainless-steel faceplate and an active-matrix LCD display with 1,600 x 1,200 resolution, a 170° viewing angle, and 250 Nits brightness. CCS provides industrial-grade computer hardware and enclosures, as well as integration, design and engineering services for OEMs and end-users.

Strongarm’s NEMA 4X operator interface pendant and enclosure (602-CW3V02-242412-RH-P9) was mounted to the coating machine. The first system to use the computer/pendant mounting configuration was the company’s Model VPC-1355, which is a medium-sized coating machine. The same configuration is now used on the company’s VPCC-60L fully perforated Containment Tablet Coater for processing potent compounds.

The computer runs two hard drives in RAID 1 format. With support for two 1 Gigabit Ethernet ports, the computer allows connection to the PLC on a private network, and the other network port connects to the user’s plant-wide and enterprise network for data archiving. Configuring network ports on different networks (e.g., 192.168.0.x and 192.168.1.x) significantly cuts back traffic, and reduces bottlenecks on both networks. It also adds a level of security to the process.

Additional slots allow use of PLC interface cards or other peripherals if needed, although Ethernet serves well in most applications. The computer’s CPU is supported by Intel 845GV (Northbridge) and ICH-4 AGPset (Southbridge) chipsets. With a built-in modem and Windows XP Professional’s ability to support remote connections, the company can troubleshoot customer problems worldwide from its Iowa location. For security reasons, such as demon dialers, customers only connect a phone line to the system when troubleshooting is necessary.

Implementing the System
Setting up and configuring the computer involved installing prepackaged software, drivers and custom-written software. One change to BIOS was necessary to allow for cycling of ac power off and on. The company installs SCADA software, which is typically GE Fanuc or Wonderware, and sometimes Rockwell Software’s RSView. Customers can choose Siemens or other controllers in place of the SLC 5/05. The company develops and writes its own software package, Recipe Workspace, which connects with most common SCADA and PLC products. Recipe Workspace is an icon-driven batch program that allows engineers to set up recipe programs for different products. Built on the ISA S88.01 State Model, the software includes phases and units within recipe parameters. The computer runs the entire system, collects all the data, logs the data to any database, such as SQL, Oracle or MS Access, and is compatible with FDA regulations.
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