A Quest For The Best Roast

An upgrade to an Ethernet-based control system enables Diedrich customers to get precise and accurate control over their coffee roasting process.

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According to the International Coffee Organization, more than $70 billion worth of coffee is sold worldwide each year—annual retail sales in the United States alone are estimated at $19 billion. With coffee being one of the few drinks considered universal, perhaps the Diedrich family was on to something when they delved into the coffee trade in 1912. What began as a family coffee-growing business has become a roaster manufacturing company known internationally for original product development and high quality. 

 

 

Diedrich Manufacturing is an international leader in the design and production of industrial roasting systems designed to apply the correct combination of heat, airflow and timing to create an optimum roasting environment for coffee beans. Based in Sandpoint, Idaho, the company offers a range of roasters to commercial operations, shop owners and even consumers. Diedrich Manufacturing ships more than 170 systems annually, with each commercial automated system taking approximately 60 days, or 1,200 man-hours, to build.

 

 

 

 

 

Three generations

 

 

Celebrating its 25th anniversary in 2005, Diedrich Manufacturing remains committed to the advancement of roasting technology by combining the roasting methods developed by three generations of Diedrichs with cutting-edge automation to achieve accurate “roast profiling.” Diedrich strives to make every machine capable of the best roast through quality of construction and depth of automation.

 

 

According to Dave Williams, software engineer at Diedrich Manufacturing, optimal roasting requires precise process control. “Our machines provide very fine control over the coffee roast, and by adding automation, our customers can maintain that one variation point or roast profile they strive for,” Williams says. “This means we need top performance from every part of the machine to consistently hit that variable.”

 

 

Declining equipment reliability and technical support limitations were threatening to impact the company’s manufacturing performance standards. To maintain the high level of accuracy and reliability of its machines, Williams and his team knew they needed to update the existing platform that controlled the machine’s roasting environment.

 

 

Machine meltdown

 

 

“Our previous vendor cited ‘user error’ as the primary reason for our reliability and performance problems—offering no path toward a resolution,” Williams explains. “Our last straw was when we experienced a complete machine meltdown and overflow as a result of a drive failure during an important plant floor demonstration. It was extremely disappointing to have the drive fail at a critical time like that, and we knew then that it was definitely time to start looking at an upgrade.” 

 

 

In early 2004, Diedrich Manufacturing began evaluating new control platforms from three different vendors, including drives, controllers and operator interface displays. While equipment performance and cost-efficiency were high priorities, equally important was the supplier’s support capabilities. After evaluating the equipment and the various supplier capabilities, Williams and his team chose Milwaukee-based Rockwell Automation Inc..

 

 

 “Rockwell Automation took the time and energy to understand the challenge we were facing and offered us a variety of solutions,” Williams says. “While I expected the product quality, I was impressed by the support and quick responses I received from the Rockwell Automation representatives.”

 

 

Ethernet-based control

 

 

The new control solution for Diedrich’s coffee roasting process includes an Allen-Bradley CompactLogix L-35E controller, an Allen-Bradley PanelView Plus 1000 touch screen operator interface running RSView Machine Edition (ME) software, and five or more Allen-Bradley PowerFlex 40 variable-frequency drives (VFDs), depending on the size of the system. The operator interface is mounted on a small box attached to the side of the machine, so the operator can monitor status of the roast. The control system is connected by EtherNet/IP, allowing remote technical support and roaster diagnostics via a virtual private network.

 

 

EtherNet/IP uses standard transmission control protocol/Internet Protocol (TCP/IP) and Ethernet technologies requiring no proprietary hardware. Also, EtherNet/IP works with either standard- or industrial-grade products, mixing the technologies for a tighter integration of information from the roasters to the enterprise.

 

 

The new Ethernet-based control system provides Diedrich’s customers with enhanced production capabilities, including automated control of roast profile, batch loading and ancillary equipment. In addition, the new automation system enables recording and duplication of exact roast parameters and process variables, including temperature control and importing and exporting of roast profiles. 

 

 

“The advanced control platform has helped us boost our efficiency and reduce our assembly times on individual
projects,” Williams says. “The reliability of the control system has minimized the amount of engineering resources we have to expend on maintenance and troubleshooting in final assembly. Instead, we now spend our time designing and manufacturing roasters—not tweaking control systems.” 

 

 

Diedrich Manufacturing first began considering the upgrade in early 2004, and by late 2004 was already shipping coffee roasting systems equipped with the new controls. In addition to improving equipment reliability and efficiency, the company has reduced its programming and engineering time by 50 percent.

 

 

“What used to take us three weeks to program now takes about three hours,” Williams says. “This saves a significant amount of money in the construction and installation of the system.”

 

 

Deidrich Manufacturing coffee roasters are shipped to customers assembled, but still need to be installed. In the past, a software engineer needed to be present at the installation, but now a compact flash card including programming code can be provided for any installer to plug in. Additionally, with the Ethernet upgrade, the roasters are now more attractive to customers because Ethernet gives them easy remote connectivity.

 

 

“We’ve been very impressed with the Rockwell Automation technology and look forward to applying this platform to further improve our product quality and performance,” Williams says. “The quality of our equipment is what has always distinguished Diedrich.

 

 

 

 

 

 For more information, search keyword “EtherNet/IP” at www.automationworld.com.

 

 

 

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