The Case to Standardize on Multi-touch HMI Hardware Today
Implementing cost-effective multi-touch panel technology sooner rather than later can futureproof system architectures
From the largest to the minute, every expense adds up in manufacturing applications so that cost control is frequently just as important as machine control. As a result, cost-conscious manufacturers may consider some new automation and control technology investments with reservations. Upgrades to Human-Machine Interface (HMI) hardware are no exception.
Industrial vendors and users generally agree that a standard HMI should include a durable touch-screen panel and the opportunity to include options such as a CPU for control as well as buttons and keys for specific functions, including a safety E-stop for just one example. Additional lighted buttons around the panel can be included based on the machine’s functions for more efficient operation in specific industries, such as plastics processing, packaging, machine tools, etc.
The point manufacturers and automation companies often disagree on is whether it’s more logical to implement single-touch panels or whether the critical mass has been reached to jump into multi-touch technology. Industrial multi-touch panels have been on the market for many years now and present operators with many more capabilities, including the ability to zoom, swipe and navigate controls through 3D HMI software.
Although “new” often translates to “more expensive,” it’s not always the case with HMI hardware. With operator interface solutions from Beckhoff, multi-touch panels are often less expensive than their single-touch counterparts when comparing screen size, build and processor performance. In addition, multi-touch panels also cut costs by futureproofing an operation. As a result, it’s possible to implement a multi-touch capable panel and operate it in single touch mode, with the option to upgrade to newer multi-touch software in the future. As a result, no additional hardware changes will have to be made, and it will be much easier to retrofit already-deployed HMI systems to multi-touch software at a later date.
HMI hardware for today and tomorrow
Multi-touch functionality delivers much more than a superficial wow factor. The technology can add meaningful functional improvements and efficiency increases for machine operators, such as the ability to intuitively find important equipment status notifications, rapidly scroll through multiple menu screens and swipe across spanning graphical representations of machine lines. It’s also possible to add additional safety features such as two hand or two-finger touch to activate certain modes of operation.
Using gestures like this might sound familiar, and it should. These interface capabilities have been at our fingertips for years in the form of smartphones and tablets. With the advances in multi-touch software as well as smartphone and tablet capabilities, machine control and visualization applications have even gone straight into the mobile age through HTML5-enabled HMI software, such as TwinCAT HMI. When using web-based HMI screens, users can quickly bring their machine HMI with them on any piece of glass. The growing adoption of multi-touch panels in industrial applications means the same mobile devices used to check work email or use apps for business can provide greater functionality for control and monitoring of machinery.
Naturally, engineers are people like everyone else and have very human evaluation of risks and rewards. Many of us are much more likely to adopt new technologies in our personal life sooner than in a professional setting. It’s understandable: There is less risk if technology at home turns out to be a “lemon” than if an equipment modernization at the factory fails. However, multi-touch-capable panels and software packages have proven for years to be just as reliable as traditional HMI systems, and that is translating to a higher market share on production floors.
High quality industrial displays have a long lifecycle and can often stick around for a decade or more, so opting for a single-touch panel over a multi-touch panel today could ultimately put a manufacturer in a tough position in the future. Further advances in multi-touch and web-based HMI software will likely create a quandary when deciding whether it’s better to remain locked into a less functional system or if it’s time to upgrade single-touch panels that still function. A better decision would be to implement multi-touch panels and simply set them in single-touch mode until the application requires the full capabilities of the HMI.
Do panel PCs possess enough computing power?
Another forward-looking trend is to reduce overall equipment and machine footprint. This begs a different question: Is it necessary to install a space-saving panel PC to eliminate a separate Industrial PC (IPC) from the control cabinet?
A multi-touch panel PC could be the right solution, but it might not be the best for all applications. Panel PCs should possess enough processing power, RAM and onboard diagnostic tools to provide an appropriate level of performance for the application.
The benefit of a passive multi-touch panel and separate IPC setup is that the panel can remain in use for years even if the IPC is updated for a more powerful model. The process is also easier to replace a passive panel if it’s somehow damaged in operation. Both passive panels and panel PCs with an integrated CPU can be fully enclosed units for arm or pole mounting, eliminating the need to create cutouts in separate HMI enclosures.
A strategy to reduce panel cabling is to use one cable connection technology. Using a simple, low-cost hardware adapter, IPCs can send DVI signal, USB 2.0 signal and power to a panel 100 meters away via CP-Link 4 from Beckhoff. This plug-and-play solution saves even more space on the production floor while providing the same flexibility to update HMI hardware in the future.
Secure on the plant floor, secure in the cloud
Either way, an open, PC-based platform is ideal when integrating HMI. The PC-based controller can run the HMI software just as easily as it can run the PLC and motion control projects. For vertical communication considerations, IPCs and panel PCs are inherently well suited for OPC UA communication. This builds in secure, encrypted data transmission in cloud and edge computing scenarios.
System security is often implemented in software and networking, but new HMI hardware can prevent unauthorized use and errors on-site. Using radio-frequency identification (RFID) chips installed in employee badges or key cards, for example, HMIs equipped with an RFID reader can authorize access to select users based on their job responsibilities. Therefore, only certain machine functions are available to employees in the HMI depending on whether they are maintenance staff, operators, supervisors or control engineers. RFID can serve as a more efficient and effective security gatekeeper that does not require manual entry of usernames and passwords.
Especially if the cost is the same or lower, it’s a smart strategy to choose multi-touch HMI hardware and ensure that panel PCs provide enough processing power for the long run. At least being mindful of the long game always boosts competitiveness in the manufacturing world. By standardizing on multi-touch panels today, a factory can prepare itself to adapt to advances for years to come.
Are you ready to update your HMI hardware and user experience with new multi-touch control panels? Contact your local Beckhoff sales engineer today.
Eric Reiner is the IPC Product Manager for Beckhoff Automation LLC.
A version of this article previously appeared in Control Engineering.