"The cheese stands alone, the cheese stands alone." The phrase may have made sense in a childhood nursery rhyme, but when it comes to human-machine interfaces and visualization systems, the concept just doesn't apply. Once simple, self-contained entities of switches and push buttons, HMIs no longer stand alone in the manufacturing environment. They are part of larger systems and must therefore be integrated with business and information systems, as well as with the devices they monitor and control.
HMIs have grown into this larger role because they now do much more than present a visual rendition of an operation or provide a mechanism for process monitoring and control. Modern HMIs are complex components in complete solutions. They are used extensively for analysis and perform elaborate system activities. These characteristics are prompting users to give increasing consideration to a systems or turnkey approach when specifying and installing HMIs.
A turnkey solution generally means using a single-source vendor or working with an integrator—or both. Such a systems approach has advantages and disadvantages. "One-stop shopping may not always get you the latest technology," says Rami Al-Ashqar, product manager, Bosch Rexroth Electric Drives and Controls, adding that a specific vendor may have the latest technology in one area but not in another.
Renée Brandt, Wonderware product marketing manager for visualization products, agrees. "Hardware vendors often want you to use their software, but it might not be the best software available for the job. It might not be the easiest to use or upgrade or integrate with other systems. When looking at a turnkey system, the end user needs to be sure that whoever is chosen for the job will select the best possible product for all the components."
In spite of the caveats, the advantages still probably outweigh the disadvantages. "By selling our own complete system—HMI, PLC, motors, drives—we are in a better position to know if there's a problem, where it is, and how to solve it," says Al-Ashqar. In addition, he adds, having a single source for service and repair means the end user doesn't have to call several people to get one thing done.
Mark Hobbs, product marketing manager, RS View, Rockwell Automation, summarizes the turnkey approach with an historical perspective: "Ten or 15 years ago, it was not uncommon to run into a customer who wrote his own custom HMI code. There weren't a lot of options, and if he couldn't find what he wanted, he created it. This is one level of turnkey system. Now times have changed. Most companies don't have the staff to do that. And they need systems that are global, not local. So they look for off-the-shelf solutions they can configure to their needs. This is another level. If that's still more than the company wants or is able to do, a system integrator (SI) or the services group of a major vendor can create the entire HMI project."
It is an interesting time to talk about whole systems as a solution, says Roy Kok, director of HMI/SCADA product marketing, GE Fanuc Automation. "Systems, not products, are what's important today. GE Fanuc's Proficy is one example of an integrated technology solution. It is a modular product. If you create something once, it is reusable elsewhere in the system. That kind of integration is hard to achieve if you buy an HMI from one vendor, a PLC from another, and a data historian from another. We recognize this challenge and Proficy is designed with an open and layered concept to facilitate layering on and integration with third-party offerings."
Turnkey HMI system controls and monitors precision vial-filling operation on a liquid filler machine for pharmaceutical packaging. An HMI system typically includes computer hardware, display mechanisms, and input devices, along with connectivity elements such as PLCs and drives. All components must work with each other and interact with plant business and information systems to achieve an integrated approach.
Importance of Planning
A turnkey approach requires a lot of upfront planning. Stresses Wonderware's Brandt, "When you're choosing someone to do a turnkey system, it's beneficial to find a supplier who has experience in the plant's own area and a good track record of successful installations. Discuss what you hope to achieve with the new system. Are you looking to upgrade old equipment? Do you need better quality? Do you have to comply with government regulations? Whoever you work with needs to know what to do and what's he's in charge of."
Adds Bosch Rexroth's Al-Ashqar, "If you're going to take this kind of approach, you need to know your purpose. You need to have a design and a plan. Who is going to use the system? What will the operators be required to do? In what kind of environment will the system operate? What kind of display is needed? And these are only some of the questions that need to be answered before you start."
The end user understands his application best, says Graham Harris, president of Beckhoff Automation. "A solutions provider or system integrator can provide expertise, but those who use the system need to embrace it as their own. We can give our experience, but only the customer can look at it all. He has to think it through from the physical configuration to the control loops to the actual displays, and make sure he has optimized every element. He needs to look at both hardware and software sides."
In this example of a turnkey HMI system from Opto22, an I/O module (top), controller, and HMI display/software work together to monitor and control a pumping system at a water bottling plant.
Turnkey systems must interface at the device level and with business and information systems. In fact, connectivity and open architecture are probably among the most significant areas of activity affecting an HMI system today. Applications of Ethernet, Web browsers for remote system monitoring and control, OPC servers for communication between disparate systems, and wireless capabilities, present expanded opportunities, but also significant challenges.
"Each individual component can be wonderful, but it's the system that solves the problem," says Russ Agrusa, president of Iconics. "The biggest problem with PC-based HMI systems is communications. An open-system solution needs to have the ability to work with data historians, pocket PCs, mobile phones, etc. It needs to integrate with the enterprise, the IT infrastructure, and an ERP (enterprise resource planning) system. If the products you're using to build your system are Microsoft-certified and OPC Foundation-compliant, you've got a pretty good shot at having your system work well together."
Achieving that seamless integration is the primary reason for using a single-source system, according to James Davis, systems engineer at Opto 22. "A thorough understanding of the project by the supplier and of open system concepts should be two primary considerations of anyone embarking on a turnkey system," Davis says. "Systems need to integrate with databases using open protocols. Discuss these aspects, discuss the entire project before it starts. Make sure whoever you work with knows what is important to you."
Turnkey systems have to work with existing systems, even if new hardware is being installed. "Most times, plants aren't replacing all of their business systems or all their controls," points out Wonderware's Brandt. "They may be upgrading only a part of their operation. A key factor is the ability to integrate with the products you don't want to change."
Visualization of the Future
Key to turnkey HMI systems is the variety of operator interface panels that provide flexibility for industrial applications, such as these from Beckhoff Automation. TFT displays come in sizes and resolutions to meet most needs and can incorporate touch screens, touch pads, keyboard, and more.
Working with a turnkey supplier or integrator lets an end user focus on business issues, observes Brandt, not on becoming an HMI or software expert. "The company can concentrate on improving productivity and quality, instead of worrying about new technologies," she says.
Observes Maria Piazza, commercial director, automation solutions, GE Fanuc Automation, "Applications are becoming more complex, and customers are making performance/price trade-offs. A flexible system solution lets them pick and choose the functionality they want and need, to build into the system a migration path that makes upgrades easy and economical."
HMI today is an integral system within a system amidst rapidly changing technology. Advances let today's HMIs provide data, graphics, and animation capabilities that, says Rockwell's Hobbs, "are truly amazing. And it will only get easier and better." An HMI solution affects the whole manufacturing process and must be considered as such. With proper design, planning, and execution, the turnkey approach can reap many benefits.
Reach Jeanine Katzel at firstname.lastname@example.org.