OEM Uses High-Speed Industrial Network for Stand-Alone Machinery

Has new Windows NT-based industrial PCs and industrial networks finally shelved standard PLC control for good? At least one forward-thinking Midwestern OEM thinks so. Appleton, WI-based RapidPak has scaled the power of a PROFIBUS network to its line of compact, stand-alone horizontal vacuum packaging machinery for food and medical markets. While the concept of a high-speed industrial network evokes images of immense, multi-node manufacturing plants, the strategy of OEMs such as RapidPak may herald a paradigm shift in machine control that resonates all the way down to even the most basic machinery.


"To the uninitiated, an industrial network on a single machine probably seems like overkill," says Ed Schultz, divisional sales manager for RapidPak and a key influence in the  PC-control decision. "PC control and a high-speed PROFIBUS network have helped us leapfrog our competitors technologically, yet remain cost competitive when you factor considerable reductions in installation and field service". Customers report annual operating costs are typically an astounding 85% less than competitor rollstock machines.


RapidPak president Ray Buchko concurs that PC control is the future of their industry for a number of reasons. Not the least of which is the company's ability to attain Wisconsin's Dairy 3A food equipment sanitation approval—the only company in its industry to achieve this rating which is stricter than the USDA's standards. With machine production expected to double in the coming year, RapidPak's strategy has not gone unnoticed, either by customers or the press, as the ten-year-old company landed on the "Inc. 500" list of America's fastest growing companies.       


The decision to integrate an industrial network with PC control evolved not out of a leading edge mentality, but—as is often the case—out of necessity. In this instance, the need for sterilization. "In food packaging machinery, especially for meat and produce, complete access to all components and invulnerability to high-pressure, high-temperature washdown is critical to avoid risks of bacterial contamination. Obviously, this has a major impact on how a machine is designed," says Buchko. RapidPak began redesigning its machinery from the ground up two years ago, starting with easily removable guards, a stainless steel frame, and solid rollers that were impervious to washdowns and cleaning chemicals. The decision to switch to touch screen PCs for control and totally potted electronics followed shortly thereafter, replacing hard to sanitize push button controls and moisture-vulnerable electronics.


Amazingly, the process to reengineer RapidPak's controls was completed in just over six months, using PROFIBUS-capable components and bus hardware from companies such as Beckhoff, InterlinkBT and TURCK. The RapidPak systems use "soft PLC" software running within Windows NT. The processor is a 133 MHz industrialized PC with an integrated modem, CD-ROM drive, and a industrial touch screen interface. Moisture-sensitive electronics are isolated in a remote electrical panel— but instead of input/output boards in a PLC rack, RapidPak uses machine-mounted watertight I/O modules from TURCK, greatly reducing wiring and panel size. The company sought to use unmodified, standard products from best-of-class providers, a move designed to "future proof" the machines and assure a stable supply of stock replacement components.


With its new strategy, RapidPak claims to have lowered its manufacturing and installation costs by simplifying wiring demands both on the factory floor and in the field. Because of the need to withstand high-pressure washdowns, RapidPak selected NEMA 4 quick disconnect cordsets and busstop® stations from InterlinkBT, along with TURCK sensors and sensor cables. In doing so, RapidPak was able to replace over 90 point-to-point wires with a bus topology—a watertight fieldbus network that considerably reduces the complexity and physical footprint of the controls. Schultz says RapidPak software engineers were also able to integrate many previously hardwired functions into the control software itself.


"A major benefit of the network is the ability to isolate and diagnose I/O errors", says Bruce Gilles, RapidPak Electrical Engineering Manager. "While clearing faults once required a long shutdown as a electrical engineer hunted through wiring diagrams, the LED diagnostic functions of the I/O devices on the network are quickly isolated, and troubleshooting can be performed easily by floor operators with a minimum of training. If there's a problem, we can usually work through it with them over the phone in a matter of minutes. Barring that, we can actually dial into the machine through an on-board modem and perform remote maintenance at a device level." While the reductions in field service costs are a huge bonus for RapidPak, the elimination of large percentages of downtime offer the customer an incentive that's difficult to ignore.


Schultz says RapidPak's arsenal of high-tech tools doesn't end there. "Currently, we're producing an on-board CD-ROM that provides all machine documentation, a backup copy of the operating system, and an interactive manual that takes the operator through diagnostic and maintenance procedures step-by-step with visual images of the components in different operational states." Schultz says the internet-capable, browser-based application will further reduce customer downtime and lessen customer service demands on RapidPak, lowering the company's overall costs. "It's truly a ‘smart' machine," says Schultz. "It can not only visually drill down diagnostics for an operator, but anticipate problems and even ensure maintenance intervals are adhered to."


As one might expect, customers are enthusiastic about the benefits. Schultz says the industrial network methodology provides a solid foundation for support of sweeping changes that are already beginning to alter the face of the food packaging and medical packaging industries. With the network's ability to enable real-time monitoring, product ID, statistical and validation feedback to MIS systems, RapidPak will be among the first to offer unit-level product verification data and tracking capabilities. With assurances of more regulatory changes and greater emphasis on food safety, RapidPak's network strategy appears to be a profound shift in how packaging machinery will work in the future. Whether scaled industrial networks take hold of machines in other industries is unclear, but the RapidPak example offers a glimpse to those considering this strategy.


This article is written and provided by Next Communications. InterlinkBT supplies bus components for all of the major open buses. They recommend and supply the best bus protocol and hardware topology to meet your specific needs. For more information about InterlinkBT or their products please visit their website at: http://www.interlinkbt.com. TURCK is a leading manufacturer of Inductive Proximity Sensors, Capacitive Proximity Sensors, Connectors, Cables, Cordsets, Fieldbuses and Automation Controls. For more information about Turck or their products, please visit their website at http://www.turck.com. Beckhoff Automation offer complete system solutions for all branches of automation and include Industrial PC, fieldbus components and the TwinCAT automation software. For more information about Beckhoff or their products, please visit their website at http://www.beckhoff.com.