Upgrade Streamlines Application Software

In this semiconductor application, the original system split interface, security and configuration utilities between HMI and PLC.

Rick Hannasch -- Control Engineering, 2/1/2007

The objectives of the control system upgrade request were clear: make process flow diagrams easier to read, increase security, and improve end-user configurable inputs and alarms. System integrator Magnum Engineering & Controls was put to the test when a global Fortune 500 Company asked for help to improve its semiconductor manufacturing process. “Our customer sells equipment that is used in wafer manufacturing and chip-making processes,” says Rick Hannasch, president of Magnum Engineering. “Each step in the process requires that special gases or fluids are introduced at precise times, durations and concentrations. Our part of the project was to build the control boxes for the equipment allowing operators to monitor the processes and change specific parameters as needed.”

The customer wish list was short and direct:

• Provide higher resolution and greater detail on process flow diagrams;
• Increase the number of security levels from 5 to 10; and
• Add functionality to user configurable inputs and alarms.

Adding this functionality, however, would overload the existing human machine interface (HMI) system. HMI functions were divided between the existing HMI system (hardware and software) and the PLC controlling the process. The existing HMI simply provided a display of process parameters. Operators made control inputs through the PLC, which ran security and configuration applications.

“The added functionality would have yielded an unmanagable PLC program,” Travis Manning, project manager at Magnum explains.

The goal in replacing the HMI hardware and software was to provide the requested resolution and detail while dramatically reducing PLC program complexity by offloading the security and configuration functions to the HMI.

Magnum engineers looked at a number of HMI products before making their final choice. One simply cost too much. Another—a direct descendant of the system’s original HMI—was deemed to require too much custom programming to be viable. Finally, they opted for an HMI hardware and software package from Beijer Electronics.

Although relatively new to the U.S. market, Swedish control component manufacturer Beijer Electronics says it is among world leaders in HMI technology.

“After the test [of the Beijer HMI] we were impressed by the user-friendly, intuitive software, called Information Designer. It features a wide selection of ready-made objects and functions that make it simple to create applications by just pointing and placing on the screen,” Manning continues.

Manning also appreciated the ability to configure applications with exactly the same view as the operator will experience. “This allows developers to visualize how the application will work in real life,” he says. “Another time-saving feature is 'off-line simulator,’ which makes it possible to test an application instantly without having the HMI connected.”

“So we had two product brands as possible solutions, one already accepted by our customer, and one less known, yet with impressive functionality and software,” says Hannasch. “Both brands offered state-of-the-art operator terminals with features and benefits that allowed us to recommend both products. Our final decision was based on the level of technical support, which we viewed as critical to the success of a project of this magnitude.”

Throughout the evaluation process, Beijer Electronics engineers and programmers played an active role in the conversion and guaranteed support for understanding and mastering the development software. “This ensured a smooth transition from the previous terminals to the Exter terminals,” Hannasch adds.

When the conversion was complete, all customer goals for performance enhancement were achieved—exceptional detail/resolution on process flow diagrams, advanced security functions and increased functionality on configurable inputs and alarms. As a bonus, the PLC code was cleaned up by including more functionality in the HMI.

The new HMIs will make it easier to make future upgrades. “Next in line is the possibility to embed ASCII text, originating from the PLC, into HMI messages,” says project manager Manning, adding that he knows a support team is working on that feature.

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