JIM GULLEDGE AND Fred Stinson log more time on the road than the average rock band. Nine weeks out of 10, the duo rolls across the state in a specially equipped 18-wheeler, delivering training to keep Georgia's production lines running smoothly.
The Advanced Technology Mobile Training Unit, nicknamed the PLC van, is a portable classroom housed in a sparkling white 40 foot tractor-trailer with the blue Quick Start logo emblazoned on its sides.
Inside are 10 workstations, each equipped with a tower computer and two flat panel LCD displays, one for the student's computer and one linked to the instructor's computer. There is a sound system, and, instead of a chalkboard, whiteboard software connects the instructor's computer to each station — all the tools that advanced technology instructors Gulledge and Stinson need to teach students how to run and troubleshoot a Programmable Logic Controller (PLC) computer program.
"PLCs are just computers," said Joey Watkins, manufacturing technology coordinator for Georgia’s Department of Technical and Adult Education, the state agency that operates the van. "It's a controller because it controls how an automated machine operates. Like all computers, it uses logic. And it parts ways with the traditional hard-wired relay system used in industry because it is programmable."
A PLC is like a brain. Instead of a computer's familiar mouse and keyboard, sensors and switches provide the input. The sensors let the PLC "brain" know what's going on along an industrial production line. Then the computer can make decisions based on that information and signal switches in response to the situation.
PLCs have become the backbone of industries that use automated machinery, from amusement parks to automobile plants. PLCs control specific manufacturing processes, like the speed of a car going down an assembly line or the number of minutes a pie stays in the oven at a commercial bakery.
The van can deliver training at a technical institute or at a client's business. "We have even given the course at sites where the plant had not been built yet," Watkins said. "All that was there was a concrete slab and a power pole."
In the days before PLCS, hardwired relay systems were the only option for operating a series of automated machines. While the old systems do most of what PLCs do, there are significant differences. For example, complete system design changes take only minutes by reprogramming a PLC versus weeks by rewiring a hardwired relay system. PLCs also report information about the system as it is in operation — how many gizmos were produced, how long it took and how many times the line shut down. Hard-wired relay systems can't do that,
"PLCs are still relatively new to the plant engineers and maintenance personnel who are working on them, so they need the training," said Roch Filipiak, maintenance facilitator for Huntsman Packaging Corp. in Washington, Ga. "I think overall, the van is an excellent tool for industry in Georgia."
Filipiak said that the training is also less expensive and more comprehensive than similar training programs. In fact, Filipiak said he would like to see programs offered more often,
Developed exclusively for Georgia companies in 1992 the PLC van program's clients have included Birmingham Steel, Edwards Bakery, Ford, GM, Georgia Pacific and Keebler, to name just a few. And demand for quality PLC training has become so great that a second van may hit the road in the next few years, Stinson said.
To keep up with current technology, Gulledge and Stinson visit manufacturing plants to learn about the problems maintenance personnel face in their day-to-day operations. As a result, the high-tech instruction is hands-on, tailor-made and up-to-date.
"I think we have a good feel for what they need," Stinson said.
In addition to teaching the ins and outs of software programs, the instructors teach their students about PLC computer hardware and stress the use of operations manuals.
"They need to know how to use the reference manuals because most problems aren't repeats," Gulledge said.
-Beverly Cox Clark
©1998 Georgia Department of Technical and Adult Education. All rights reserved.