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.
3. Security and safety
Modern HMIs are equipped to do a better job of securing data as well as protecting workers’ physical safety.
“I think security is becoming a bigger focus than it has been in the past, which is a good thing,” says Clark. High-profile break-ins in the industrial sector, such as a cyberattack that disrupted control systems at a German steel mill in late 2014, are demonstrating the critical need for more airtight controls security, he says. HMI designers are rising to the challenge by incorporating greater user access control features and stronger authentication of devices.
The use of GPS coordinates in the field or specific machine log-ons or bar codes on the factory floor can allow access to asset control information via specific mobile devices, Clark notes.
“People can use HMIs as gatekeepers into control systems,” says Clark. “The HMI, by virtue of the fact that it either has its own security or uses a larger security system ... can protect control systems by simply segregating them or doing housekeeping for them,” such as by aggregating data to an ERP system, he says.
In addition, preset and customizable security levels for HMIs can help ensure that users access only information relevant to their role, Tucker says. A supervisor can say, “I know this person only needs to be able to view this screen,” she says. “Maybe that’s the factory manager who’s looking at OEE – he’ll only be able to view that one screen ... That’s how you get the right information to the right people.”
Besides supporting data security (and promoting efficiency of data use), today’s HMIs can protect workers by, for example, requiring screen manipulation that keeps workers’ hands out of harm’s way during machine startup.
“With multitouch, I can force an operator to touch two corners of the screen to activate a machine, like a press,” says Stone. “From an OSHA safety perspective, I’m putting your hands on the touchscreen so the press doesn’t have your hands on it when it activates.”
4. Flexibility / interoperability
Besides enabling more-modular approaches to factory design and operations, today’s HMIs offer more flexibility for interacting with each other and with other operating systems.
“I can have a mixed environment now” in terms of brands of HMIs, SCADA software, and PLCs, Stone says. “A lot of companies are coming out saying, ‘I’m going to start to create my software … so that it talks to multiple types of data acquisition systems,’ ” he says, including HMIs. “That makes my changeover, particularly for factories, for manufacturing, so much simpler.”
Mobile devices’ migration to the plant floor is helping drive this trend, says Clark. He notes that his company’s InduSoft Web Studio software can run on any mobile device that has an HTML5-compatible browser.
Stone also sees mobility as driving major changes to the HMI market. “We’re going to start to detach from necessarily having HMI be mounted to the machine,” he says. “We’re talking more and more about using just a tablet.” Software is driving applications, Stone notes, and it’s running on lightweight operating systems such as Android and Linux.