The Industrial Internet of Things promises to make factories more productive and agile through connectivity, cloud computing and data analysis. This new era in industry relies on a host of tools and technologies, including sensors, actuators, software, low-power wireless networks and device monitoring.

One area within industrial plants that is adapting to these changing dynamics is the human-machine interface (HMI). At its most fundamental level, the HMI allows machine operators to monitor equipment and respond to changes. In recent years, however, it has evolved into a central system enabling data-driven decision-making in an increasingly mobile environment.

Past Shortcomings

Two decades ago, HMIs typically comprised either an electronic panel that displayed a few lines of text or a rudimentary graphic of a machine. Many legacy HMIs had too many colors and moving pieces that muddled the screen for the operator.

The FactoryTalk View Machine Edition allows for operator interface across multiple platforms. Image source: Rockwell Automation.Information clutter also became a problem in the case of larger distributed HMIs controlling disbursed geographical assets. Over the years, these systems have expanded beyond a classic operator interface into “a one-stop shop for any type of new company initiative,” says Scott Miller, business manager of visualization software at Rockwell Automation.

“If you wanted to do things like quality management or Lean Six Sigma concepts, HMI was a convenient choice because it was one of the only applications on the plant floor,” he says. That complicated things for machine operators who were trying to control processes within a daunting stream of content meant for other users.

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Standalone HMIs continue to populate plant floors, monitoring only one variable and acting in isolation from other processes. Such disparate systems create a data vacuum, says Richard Clark, controls engineer at InduSoft Web Studio from Schneider Electric. Without access to big data to help pinpoint process bottlenecks and irregularities, operating efficiency can suffer. And those legacy systems can be a challenge not only for young operators to work with but for maintenance staff to keep in service.

Modernizing the HMI

HMI software and hardware designers are refining and adding capabilities that leverage growing connectivity and data sets without hindering a machine operator’s job.

With more manufacturing and process facilities adopting industrial PCs, many HMI systems now run on standard operating systems such as Windows or Linux in lieu of proprietary software. What’s more, modern HMIs not only talk to a variety of equipment and protocols, but they share data to local and cloud-based historians.

Design guidelines from industry associations aim to simplify display graphics to improve the user’s ability to detect, diagnose and respond to an abnormal situation. Older HMIs that still rely on text-based screens or poor graphics “create operational difficulties and limit operator access for process improvement without a great deal of manual effort,” says Clark.

Higher-level interfaces allow operators to look at numerous levels within multiple production lines. HMI developers also are prioritizing ease of configuration, given that workers “already are overstressed by having too many expert systems they have to stay on top of,” says Pat Cooke with HMI/SCADA software maker Trihedral.

For those HMIs that still serve as a general repository for information, enterprises are evaluating ways to redirect data flows into other systems. Doing so offers another way to make the HMI more intuitive for the operators. As Rockwell’s Miller says, “you should not be providing operators with information they don’t need because it affects their situational awareness.”

At the same time, modern HMIs make the same data available to different groups within an organization. “It’s no longer just the operator or maintenance engineer, but people like quality and line supervisors also need to have access to real-time information to make better decisions,” says Chirayu Shah, product manager of information software at Rockwell Automation.

Between Cloud and Island

An ongoing concern for plant engineers is how to store all the data generated by machines that connect to each other and the Internet. All of an organization’s data won’t reside in the cloud, but keeping it in separate islands doesn’t work either, Miller says. As such, the HMI ends up being what he calls a “blending point” between the cloud and the island.

Another critical function of the HMI is managing alarms. Historically, the alarm database was a separate component to the HMI server. Rockwell, for one, has built the alarming system into its controller and HMI. In doing so, users can monitor alarms even if they are disconnected from the network.

“When a burst of alarms occurs, you now get much more accurate timestamps, as well as the right order of alarms displaying on your HMI screen,” Shah says. Productivity and runtime also may improve because everything is already integrated in the control system.

Additionally, new standards such as ISA/ANSI 18.2 focus on ways to develop better alarm strategies and methodologies to help reduce and rationalize alarms. “Many operators routinely find themselves sorting through thousands of alarms to find a few that really matter,” says Richard Carpenter, general manager for controls platforms with GE’s Automation and Controls business.

HMI from Anywhere

The proliferation of mobile devices has changed how operators and engineers do their jobs. Not surprisingly, the operability and accessibility of today’s HMI systems mirror that of consumer electronics.

TwinCAT HMI software scales the display according to the device. Image courtesy of Beckhoff Automation.“It is now common to have multi-touch functionality on the HMI hardware for the kinds of gestures typically used on tablets and smartphones,” says Daymon Thompson, automation specialist with Beckhoff Automation.

Technologies such as HTML5 enable the connectivity and portability of HMI software so that operators can monitor equipment from anywhere and respond to critical events. Programs now scale and format automatically to suit the display for use, whether it’s on the machine, a laptop or a cell phone.

Often, the requirements of a mobile user are different from the equipment operator. For example, a mobile user might only need to see a few line variables rather than have the entire HMI run on a smartphone.

Providing access to one slice of the HMI application allows nontraditional users to access traditional HMI data “without a lot of difficulty so that they can do their job more effectively,” Rockwell’s Miller says.

Beckhoff Automation’s Thompson also sees organizations implementing push notifications and apps for mobile devices used by plant personnel. Doing so requires “even deeper integration with the HMI and automation controllers,” he says.

Addressing Limitations

Despite the progress in HMI capabilities, challenges continue to dog industrial plants in implementing new systems. One is the discrepancy between aging plant-floor technology and a generation of workers raised on touchscreens and interconnectivity.

Modern HMI design extends to mobile devices for remote monitoring and control of equipment. Image source: Rockwell Automation.In a recent webinar from Rockwell on modern HMIs, more than half of participants said their HMI was more than 10 years old. Yet more than 90% reported that their HMI engineer was under 30.

The young workforce entering the factory “is armed with newer technology that they learned at school, but they have been asked to manage these older systems,” says Shah.

Similarly, “it is becoming increasingly difficult to find trained people who can still work on older equipment,” InduSoft’s Clark says. Both scenarios could lead to inefficiencies and gaps in performance.

For many plants, the reluctance to shift to advanced HMIs is rooted in cost and, in some cases, skepticism over a new HMI system’s capabilities. But as Clark sees it, taking months to redevelop old HMI screens or hiring expensive engineering firms to redevelop older purpose-built HMIs “just won’t work in a modern agile factory.”

Modern HMIs can offer easy-to-understand graphics, better event response and improved visibility throughout all levels of an enterprise. That leaves industrial plants with big decisions about how to leverage their HMI systems to boost productivity and uptime in the age of mobility, big data and the Industrial Internet of Things.

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