Operator Interfaces Become a Communication Nexus

Leveraging advances in the PC world, human machine interfaces (HMIs) are experiencing both a technology boost and a significant change in their strategic role. Backed by fast Intel Atom processors, inexpensive memory, larger screens and more powerful operating systems, HMIs are becoming a vital link for communication between the factory and enterprise business systems.

Driven by these new technologies, SCADA and data logging functions are landing on the HMI, and there is a potential convergence with routers and switches. In addition, mobile devices are opening new HMI pathways for visualization using remote connectivity solutions. These changes are likely just the beginning of a shift that is moving HMIs toward the center of machine design as panels increasingly occupy a central, pivotal position in future design innovations.

HMI is the Crossroads

"From the machine design point of view, we're going to see the HMI more and more as the nexus for communication," says Mike Granby, president of Red Lion Controls. "It's the point where all the devices on the machines come together, at least on a strategic basis, to share information and also to pass that information upwards to high-level systems."

The HMI is not only the nexus, but also serves as the gateway that passes that information to the management system in the factory. Obviously, the role of the HMI has changed dramatically from a push-button replacement in years past to an advanced visualization tool performing protocol conversions and connecting all of the items in a panel. Data logging has become an important function, and is being used to record everything going on in the machine including faults, performance tracking and scheduled maintenance.

"I would say that the dual Ethernet HMI we have been introducing on HMIs has been our most significant new product," says Granby. a euro S"Modems have also been very significant, and Crimson 3, our new software package, makes it a lot easier to get to three key features: data logging, protocol conversion and Web servers."

He says dual Ethernet is exciting technology because users typically have one network on the machine with fixed IP addresses doing all of the control functions. If you want to connect this machine to the customer's IP infrastructure, but only want one IP address and have it protected, you can use a firewall box. a euro ..."But if you want an industrialized one, it's not going to be cheap and it's another point of configuration," Granby says.

Mainstream IT Inside

"The great thing about HMI if it's PC-based, is that it can follow what's happening in the consumer, IT and mainstream computing worlds," says John Kowal of B&R Industrial Automation. "We have certainly seen the Atom processor provide a big boon. It's designed for mobile computing, so it runs very cool, allows suppliers to provide completely sealed HMIs, and the prices are great. We have had some units that have 40 percent less cost because of the Atom processor."

Kowal says we are going to see a convergence of consumer and industrial software in the HMI space over the next couple years. Convergence usually takes longer in the industrial market, but he sees it happening with a lot more Windows applications on the HMI for safety, security, OEE (overall equipment effectiveness) and MES (manufacturing execution systems) applications.

"Everything affects everything else. I think we are going to find that the same types of data points that you're looking at for one reason, you should be looking at for multiple reasons and the applications shouldn't be siloed," Kowal says. "We have been talking about putting animation on HMI for training and walking through maintenance procedures so that the operator can develop better understanding and retention."

"The latest trends we see are the commercial market helping to drive down pricing through the influence of products such as the popular Netbook PCs," says Greg Philbrook, HMI/communications product manager for AutomationDirect. "Most of these trends have been incredibly beneficial. Faster processors at lower prices are available to the manufacturer, and more options for inexpensive memory are giving us an ability to improve our offerings."

Philbrook says that while most HMI panels have been based on processors from 200 to 400 MHz, the range is now moving up to 400 to 800 MHz at the same cost. What that does is open up more performance and power for adding more features and support, without sacrificing performance for the operator. The primary purpose of the interface is still the operator, and the challenge is to provide connectivity, functionality and advanced features such as animation without affecting the actual interface performance for the operator.

"More and more customers are taking advantage of the advanced functionalities like remote access, Web and e-mail capabilities and FTP file sharing. These features are now an integral part of the latest HMI products," says Philbrook. "What we're basically seeing is the advanced features that were once only supported in the more advanced PC SCADA systems, merging with the operating interface hardware. The HMI or operator interface panel is in essence becoming a gateway to the enterprise system. Expectations are being raised by end users as far as what they can do, but they still don't want to forfeit performance for operator control of the application."

A Portal and a Bridge

"The trend we see is more and more SCADA functionality pushing down into the panel level, especially in the smaller devices," says Alan Cone, product marketing manager for Siemens Industry Inc. "This includes networking between devices, the ability to share information instead of being a standalone island, as well as all the Web activity such as remote diagnostics and control."

When we first started seeing HMIs on the factory floor, they were primarily push-button replacements. The HMI was typically communicating with a PLC controlling the machine, with any data logging performed by the PLC. If the user needed data, the data was transferred from the PLC up to a SCADA system and the operator terminal was strictly an operating terminal.

"But what we have seen over the years, and it keeps expanding, is use of the operating terminal as an information portal," says Cone. "The PLC runs the process and all the communications, as well. More machines are sharing data and, if it's not critical runtime data, using the PLC to control the process. Data sharing is up in the HMI layer where, in the past, the only way you shared information was SCADA systems networked together."

Now, users are collecting information using compact machine-level HMIs and sharing data between machines or building small control room-like settings in the operation areas. a euro ...This approach provides for a lot more distributed control out on the factory floor, as opposed to bringing everything back to one massive control room with one large SCADA system.

"Some of the advantages of putting data up on the HMI level is you might have OEMs building machines with different control mechanisms or processors," says Cone. "Instead of an Allen-Bradley PLC, talking to a GE PLC, talking to a Siemens PLC, you can use a common HMI platform and share the information. Information is passed back and forth on the HMI level without the past nightmare of getting these separate protocols to communicate. The HMI is the bridge."

What this creates is a different role for the HMI in machine designs, and an ability to easily display more information for the operators. It's facilitated a change from a focus on the basic control screens to a view of the total machine and presenting information in a more appealing way. "As we're seeing pricing trend down, we're seeing customers move up to larger screen sizes," Cone says.

One trend is more HMI suppliers moving away from the 3x4 format and following the commercial LCD market to the widescreen 9x16 format. In 2011, Siemens plans to introduce sizes from 4 to 12 inch, and later in the year introduce sizes up to 23 inch with the new HMIs moving to the widescreen format.

He says there are some competitors starting to bring video feeds into their HMI devices but, more important, is the ability to run office applications as well as media player. a euro SThe focus is on the ability to run media files and view PDFs such as maintenance manuals on the HMI. Using Windows-based HMIs provides an ability to use a Web browser, Word, Excel, PDF viewers and media players on four-inch devices.

HMIs for Soft Control

Cone says that one ongoing trend in HMIs is the emergence of the soft PLC to run control tasks on the HMI. For years, Siemens has had a soft PLC engine able to run on a CE platform, but the future direction is a new line of low-end industrial PLCs using Flash drives and the Intel Atom processor.

"This approach boosts our processing power and will be our future platform for the soft control engine," says Cone.
"Users can run the soft PLC in a CE environment, but with Windows 7 Embedded and Windows XP Embedded being more solid products, there is a lot more confidence on uptime to be on those platforms versus the compact CE operating systems for soft control applications."

He says some users who moved down exclusively to the CE world want to get back between running CE and the full Windows desktop operating systems. The advantage is to leverage the benefit of higher end processors and more robustness from Windows, and gaining more flexibility than in the CE world.

"Users used to say they didn't want the hard drive and blue screen of death on the factory floor, so they opted for CE which is very dependable and employed solid state hard drives that are more robust than normal rotating media," says Cone. "But the openness wasn't there in the CE world because every application is built for a specific device and any additions required rebuilding the CE image."

Now the trend is moving toward having more desktop operating systems running on Flash drives. Heat output which used to be a concern is different because many newer processors use less power and thereby reduce heat dissipation, which used to be a problem with PCs. But now, more robust embedded operating systems that offer the flexibility of adding more custom applications is generating renewed interest in this area.

IT Infrastructure Convergence?

Conceptually, the HMI is in a key position to handle the details of the control system and assist with supplying the needs of the enterprise system, as well. One potential trend in this areas is convergence between the Ethernet routing and switching worlds and the HMIs on the machine. "I think you can see they both logically sit in the same place, and both have access to the same data. So it makes sense to leverage that position to get greater value for the customer," says Granby of Red Lion Controls.

All of the firewall functions in the router could move into the HMI because it's naturally connected to it, or perhaps switch modules may be added to the back of HMIs. One thing seems certain: As computing power continues to increase, it makes sense that additional functions will centralize on the HMI.

Spectris, Red Lion's parent company, acquired N-Tron, a company that makes Ethernet switches, late in 2010. "We are excited about that convergence and tend to approach it slightly differently from the primarily SCADA or Linux/CE-based system vendors," Granby adds. "We are looking for solutions with much higher availability that are much more hardened against attacks and with a greater security orientation because we see that as a key driver. The goal is high availability, quick boot times and a very small footprint for virus penetration."

3-D Animation

Another emerging trend is use of animation that's 3D and interactive to provide rich content on the HMI, as opposed to just video or operating manuals as PDFs. When the HMI is not fully Windows-based there can be difficulties running these applications, but the push toward Windows XP embedded and other operating environments enables improved handling of third-party animation and software.

"It allows you to do things like run animation and OEE software and, if you're looking for productivity improvements, it's also good for sustainability because you're producing less scrap," says Kowal. "A machine that is safer is going to have less downtime, be more productive and the enabling technologies are all in the software that resides on the HMI."

Animation offers another interesting potential for improving the HMI. Using immersive 3D, customers can provide ongoing training for personnel. If the operator is learning to do a product changeover, the animation will reinforce picking the right change parts and, if they pick the wrong change parts, let them know immediately. So there's very quick reinforcement and learning that's very valuable. Typically the animations are developed from a 3-D model such as SolidWorks.

From a practical and cost standpoint, the use of animation is still developing. From a technical standpoint, animation has been around for years, the software is available and the people with the necessary computer graphics skills are out there. But it's harder to justify when an OEM is building 100 machines a year, given the time required for software development. For this reason, B&R Industrial Automation is working with Purdue University Calumet to provide machine builders with a business model using interns and a licensing arrangement to develop animations for use in packaging machines.

Mobile Devices as HMIs

"We see the definition of the HMI platform expanding to a wider range of devices. When you see users walking around plants doing visualization with iPhones and iPads, it is the result of more and more suppliers responding to their customer's demands for these types of solutions," says Craig Resnick, research director for ARC Advisory Group.

Resnick says most in-plant mobile device use is for visualization. "We're not at the point yet where we're seeing extensive control decisions being made using mobile HMI devices. But at least for visualization and maintenance, this has been one of the major trends," he says.

Another trend has HMI applications moving from simple visualization of flows, levels, temperatures and pressures to becoming an information portal providing MES data. It's being used for production management visualization of digital dashboards, OEE and other key performance indicators.

From a technology viewpoint, closed HMI platforms where proprietary software is embedded into the device has evolved to open HMI platforms running off-the-shelf, shrink-wrapped HMI software which is typically based on a Windows operating system. Because of the wider variety of HMI devices, the HMI software is becoming less operating system dependent. HMI software is still used on PC- or server-based systems running Windows 7 or Server 2008, but HMI software embedded on handheld notebook-type devices might be using a runtime version of Windows CE, for example.

As the HMI becomes more distributed, Resnick says the central operating system will often exists someplace else. When users pull out an iPhone or iPad, obviously the central operating system isn't an issue because the system is running in a server that could be within the plant or on the other side of the planet.

"I think what you're going to see is that cloud technology is enabling the potential, and I say potential because there is obviously not a lot of cloud applications that have currently been deployed, but there is potential to have HMI in the cloud," says Resnick. "The software could be hosted by one of the many HMI software suppliers, where they not only would be able to supply the visualization software for the plant, but would also be able to provide upgrades, maintenance, service and revisions, offering manufacturers a solution to outsource the management of their HMI software."

"If the recent trend is thin clients, third-party software and doing HMI on the Web, this outsourcing is an extension of the third-party solution," says Resnick. "The thin client moving into the cloud would drive the ability to use these wireless handheld HMI devices. I think that's where you are really going to see that market take off."