Tim Stone, an engineer turned product manager at Advantech Corp., remembers the days when a human-machine interface (HMI) meant an “ugly LCD screen and push buttons and all that stuff.”
“To be frank about it,” he says, “it wasn’t all that functional, but it served a purpose, which was, ‘I’m going to get to the next level of controlling a manufacturing process by having something that I can look at and respond to.’ ”
Fast-forward a few decades, and users can control industrial processes ranging from machine operation to parts purchasing from virtually anywhere in a facility in much the same way they’d interact with their personal tablet computer. The beautiful paradox of the evolution of HMI technology is that even as HMIs have been adapted by a wider range of industrial users for a wider variety of applications, they’re becoming more personal.
It’s a fact that’s remarkable, even if it’s not totally unexpected, given that the trend of more power + greater user-friendliness has played out extensively in consumer products, maybe most notably in mobile phones.
Advances including gesture control and multitouch operation, better built-in security, and expanded interoperability (the ability to play nicely with other control systems) are making HMIs capable of aiding in industrial asset management in unprecedented ways. Here, a look at four ways in which today’s HMIs are better than ever.
1. Sheer capability
“HMI is not just for the machine operator anymore,” says Marissa Tucker, product marketing manager of controls and HMI at Parker Hannifin. “You have people, for instance, in purchasing, who may want to get information about how much material has been used, how much is left. You may have someone on the factory floor saying, ‘How much scrap was created and why?’ Or you might have the FDA come in and say, ‘I need to audit you guys. Give me your records of who was operating this machine at this time.’ ”
Thanks to greatly enhanced communication capabilities that allow today’s HMIs to “talk” to each other, to SCADA systems, to enterprise resource planning (ERP) systems and manufacturing execution systems (MES) and more, users can now easily answer those questions, Tucker says.
When important data such as temperature measurements from a given machine can be sent from a PLC to an HMI and stored there for any user who might need access to it, HMIs are empowered to support more-efficient decision-making, say Tucker and Richard Clark, an application developer for InduSoft Web Studio at Wonderware by Schneider Electric.
“I think that the biggest thing that people don’t realize that HMIs are capable of is the fact that they can be a gateway,” Clark says. Beyond monitoring and controlling a machine in real time, HMIs can provide easy access to a wealth of information about that machine’s performance over time, best practices for the machine’s operation, and even troubleshooting assistance – whether the HMI is running on a control panel on a machine itself or on a mobile device.
This could be as simple as having an HMI store manuals or how-to videos, Tucker says, or it could mean allowing for a machine operator to interface directly via video or text chat with a product expert from the original equipment manufacturer to help solve problems.
Says Bob Argyle, chief customer officer at Leading2Lean, a cloud-based visual management platform provider: “On the plant floor, this means that instead of limiting the HMI to controlling and operating the machine, it can also be leveraged to provide and pull data and reports from other systems [e.g., ERP, CMMS, and MES systems], giving the shop floor additional visibility to help solve problems more quickly and reduce manual data entry.”
Gesture control and voice commands, two functionalities on the rise in the HMI market, further enhance HMIs’ usability. Clark says InduSoft Web Studio HMI software can recognize “every kind of gesture you could possibly think of – sliding, moving, pinching, twisting” windows on the screen and more. This functionality is familiar to (and comfortable for) users of consumer mobile devices, and adopting HMIs with these advanced capabilities can help serve another leading goal of manufacturers: attracting top talent.
“One of the challenges companies had is attracting the tech-savvy, digital-native generation to (industrial) jobs when the equipment that they had was really from the 1970s,” says Andrew Stuart, solution manager at Honeywell for the Experion product suite.
Companies know they need to hire replacements for operators nearing retirement, he says, “and they obviously want to attract the best people.” HMIs that function more like the smart consumer products that workers use at home on a daily basis not only are more appealing to the digital-native generation, Stuart indicates, but also they’re simpler for all workers to adapt to.
Devices that support multitouch commands are “really like the iPhone or the iPad – very intuitive,” he adds.
In addition, HMIs can serve as a backup – a manual failsafe – for autonomous products and processes. Advantech’s Stone notes that one company he’s working with has an HMI screen mounted to its robotic forklift trucks, which should, in theory, be completely remotely controlled and able to maneuver seamlessly and autonomously through a virtual grid to find, retrieve, and place items.
So why does a robotic lift truck need an HMI? “Because every once in a while, it gets lost,” Stone says. “And someone has to walk up to the unit and get it back into the grid. That’s stuff that happens from time to time. Or things malfunction – the batteries malfunction in the forklift or something else happens. (With an HMI), you have the ability to deal with that individual unit.”
Wider use of HMIs reflects the modern, modular approach to factory design and operations that’s being driven by Industrie 4.0 out of Europe, Stone suggests. It’s “the idea of being able to reconfigure my plant as my needs change,” he says. The role of humans on the factory floor or in the control room increasingly is to oversee these more-flexible operations, implement and monitor on-the-fly changes, and, as Stone says, “keep all this flowing.”
One size does not fit all when it comes to human-machine interfaces. Different users, first of all, have different needs depending on their role in the plant when it comes to the machine information they need to access. Furthermore, they’re approaching their job and their use of an HMI from different backgrounds – in terms of experience, the language they speak, even their physical characteristics.
HMI providers increasingly recognize this and are offering new options to make HMIs easier to use in a multitude of ways.
From a physical perspective, “We’ve seen screens go from being, let’s face it, 6.5-, 7-, 8-, 9-, or 10-inch screens to, with some of these widescreens we’re producing, 21.5-inch screens,” Advantech’s Stone says. “Now I can put a lot more information on-screen, and you don’t have to strain your eyes to see it.” (Control-room HMIs are even more expansive: Honeywell’s Experion Orion control-room console, Stuart notes, offers a 55-inch, high-definition frame.)
Stone adds: “We used to talk about the days when people would poke at the screen with a pencil or a screwdriver or whatever because the buttons were so doggone small.” Plus, he points out, “In the old days, we would just slap an HMI on the side of a panel, and if it was tough if you were too short or too tall.” HMI providers today have a greater appreciation for ergonomics – especially for those who spend much of their workday staring at a screen – and the need for screen adjustability, anti-glare technology, and other features. “It’s more about, ‘How can I make this operator’s world get better?’ ” Stone says.
Part of making the operators world better is giving them easy, intuitive access to the information they need to do their jobs. And this involves displaying more (and of greater importance, more-useful) information right off the bat, Stuart and others say.
“We’re trying to put more information in the operator’s primary field of view,” Stuart says, giving easy perspective and context to multiple processes and machines running at once, so as to enable faster and better decision-making – no clicking back-and-forth through multiple screens required.
But there’s also a balance to strike between the volume of information shown at any one time and ease of use of the HMI, observes Trevor Lang, a product manager at Schneider Electric.
“We have to balance mission-critical vs. ease of use,” Lang says. “I think there’s a balancing point; it’s just a matter of finding it.”
Tucker calls for simplicity without being simplistic. “One of the things that we have seen in this century, because all of a sudden HMIs have these huge, massive processing capabilities, (is) everyone was so excited that they put every possible thing that they could on every single screen,” she says.
It was thought, she explains, “that if we put the entire schematic of (an) entire machine on every single screen, it would help debug issues.” Although it’s great to have a schematic readily available, Tucker says, if it dominates an operator’s view on an HMI, “what we find is people miss alarms because they’re not in-your-face enough – people miss critical data and information that way.”
Companies evaluating new HMI solutions, Tucker advises, should consider that “the most important thing is making sure that (operators) have all of the information that they need for a particular step and use that they’re on, and no more than that.”
In addition, if an alarm should crop up, “it needs to be proportional to the problem,” she says. “If there is something stuck in the machine, a jam detected, and there’s going to be a potential loss of production, that needs to take up half the screen.” Lesser problems don’t need the same treatment; it’s about scalability, Tucker says.
Recognizing that operators of different skill levels and backgrounds will need to use the same HMI in today’s plant, HMI providers are offering more options that take these variables into account. “Let’s say I’m a new operator,” Stone says. With an “intelligence key” built specifically for new operators, users can easily access basic information about machine operation or troubleshooting at the point of contact. “In case of a jam, I click on (the key), and a little YouTube video pops up and shows me how to fix it safely,” he says. Safety checklists, too, can come in handy for new operators or in dealing with machines on which operators rotate frequently.
Finally, an increasingly diverse plant workforce necessitates greater language flexibility for HMIs.
“Language support is so critical – it’s absolutely important to be able to have a means of easily translating,” Tucker says. Parker Hannifin’s Interact Xpress Manager, developed as a solution for distributed applications where several HMIs are deployed on one machine or across multiple remote stations, according to the company’s website, allows for on-the-fly language changes. Through a spreadsheet button, a user can quickly change the HMI’s display to another language.
The bottom line on HMIs today, Stone says, is this, reflecting a new attitude on the part of HMI makers and users: “Instead of forcing the machine and the operator into the programs world,” he says, “let’s force the program into the operator’s world. It’s a whole lot more human-friendly.”