Allen-Bradley ControlLogix PLC and RSView SE human-machine interface from Rockwell Software.

“We took the customer’s paper-based recipe system and came up with a scheme to enter their recipes in RSView,” reports Gurney. “The software links to the operator interface. Trailblazer has a bunch of different products, so we developed a custom recipe manager and made a call to RS View to do the operator interface. The operator enters batch information into the system via this operator interface. The recipe is a series of steps. Each step enables a series of options specific to their system. They can set up every step including an end-of-step type that the operator can enter and acknowledge. This makes for a very flexible and interactive system.”

Initial setup consisted of entering the recipes and saving to a master recipe list with a unique number. The system handles routing and control programs that need to be set. Although some manual process set-up still exists, such as loading material, when the manual step is activated, a photo of the right set-up pops up on the screen.

Too many cooks

Too many cooks can spoil the broth, they say, and one way they spoil it is by contributing to unwanted variability. Batch processors that have traditionally used manually intensive production systems involving too many operators can benefit by installing computerized controls to yield:

•A decrease in recipe changeover times

•An increase in product consistency and quality across a range of operators and operator skill levels

•Increased productivity for one cook via automation of mixing and material handling operations.

These are among the benefits Trailblazer Foods now takes advantage of since it implemented the process improvement strategy recommended by Concept Systems.

Once the batch recipe system was in place, attention turned to the packaging line. Here the problem was that each machine on the line was built by a different original equipment manufacturer. As Concept Systems’ Gurney explains, each machine has its own control system distinct from the others, and the various control systems do not communicate with each other or anything else. “Our goal,” states Gurney, “was the integration of the various systems such that the packaging line would know what products were in the process of manufacture and could be automatically set up. For example, there are different bottling processes for jams versus jellies.”

Since the packaging side of the business was not fully integrated with itself or with the processing side, Control Systems used an Ethernet network to tie the conveyor system to the supervisory system built for the batch process. The network system uses EtherNet/IP, an industrial network using the common industrial protocol (CIP) standard of ControlNet International. The network is supervised by an Allen-Bradley ControlLogix platform.

Although some of the packaging machines are tied to the system in order to obtain a minimum level of integration, the main part of the integration is achieved through the conveyor system. Absolutely critical is careful control of the amount of time product spends in the cooling tunnel. This system contains about 25 Rockwell Automation Powerflex 70 variable frequency drives—all speed coordinated. “One of the keys to the system,” states Gurney, “is that we can control the backlog of product into the packaging stations to assure maximum throughput.”

Some might be leery of using Ethernet in a manufacturing setting, but Gurney says that Concept Systems has had a lot of success with it. “We know how to take advantage of EtherNet/IP, and have been using it even down to the Remote I/O level,” he adds. “The biggest feature right now is the huge bandwidth. It is high enough that the non-deterministic nature of the network is not an issue any longer. Another benefit is the ease of access to components. Many are commercial, and therefore, easier to find and maintain—not to mention less expensive than fieldbus components from ControlNet or Profibus.”

The biggest benefit to Trailblazer after implementation of this system is decreased set-up time, according to Gurney. Set-up is automatic in many cases. An additional benefit is the elimination of the necessity of “tweaking” set-up parameters that often leads to a loss of product during this process.

Improvements like these have positioned Trailblazer Foods to compete more effectively in a marketplace that continues to put more and more emphasis on flexible recipe management and smaller batch sizes.