Improve remote HMI and OIT access

Mobile HMI: Smartphones and tablets combined with industrial software can improve remote access to human machine interfaces (HMIs) and operator interface terminals (OITs). Mobile workers demand remote access solutions optimized for smartphones and tablets. Fortunately, there’s an app for that.
By Marcia Gadbois and Jeff Payne April 1, 2014

Figure 1: Apps developed by HMI software and OIT hardware providers provide users with a superior remote access experience as compared to browser-based access. Courtesy: Indusoft, Invensys, and AutomationDirectManufacturers and process industry companies expect human machine interface (HMI) software and operator interface terminal (OIT) hardware to deliver remote access to devices, including desktop PCs, laptops, smartphones, tablets, and other devices. Internet connectivity and mobility can improve overall operations, and HMI and OIT solutions can deliver the functionality and features they need.

The growth of the Internet and its connected devices has changed how we live and do business. Activities once deemed far-fetched or prohibitively expensive, such as conducting a video call among participants from different continents, are now part of everyday life. Today’s smartphones and tablets have more computing power than the mainframes that filled entire rooms a couple decades ago. As a result of these advances, business is becoming increasingly mobile.

This paradigm shift is occurring in the automation world as well. Today’s manufacturers face the same challenge as other businesses: how to do more with less. Some of these changes are attributed to a fundamental shift in how manufacturers have done business over the last 10 to 15 years. From Lean manufacturing to Six Sigma, most of today’s plants have implemented some type of continuous improvement initiative to cut inefficiencies, improve quality, and reduce energy use.

This focus on operations is also gaining momentum because more businesses face budget restraints and shortages of trained personnel. Many companies can’t afford to hire more workers, while others are trying to cope with the retirement of experienced staff.

Today’s markets demand that businesses must operate and execute in real time. To meet this goal, manufacturers must be able to retrieve and act upon data from anywhere in the plant or outside it to remain competitive.

Fortunately, the Internet and its related technologies are helping manufacturers overcome these challenges. Specifically, the growth in dependable remote access to human machine interfaces (HMIs) and operator interface terminals (OITs) is one of the methods being used by companies to reduce costs while improving operations. 

HMIs, OITs, Web browsers

The introduction of PC-based HMIs and the subsequent move away from proprietary systems to ones based on a standardized platform (Microsoft Windows) could be considered the first step toward remote access. The standard network protocols found in PC-based solutions facilitated communication among diverse equipment and systems, ending the isolation of automation processes.

Following closely were OITs based on embedded Microsoft Windows operating systems. OITs were less capable than PC-based HMIs and much less expensive to purchase, install, and maintain. This made them a better fit than PC-based HMIs for many lower-end and embedded applications, such as providing the operator interface for a simple machine.

Users were initially content with simply viewing information from multiple machines or processes on PCs running HMI software located in the control room. Each PC was loaded with its own HMI client software, which often required separate, expensive licensing. The PCs were typically connected to plant floor or field-mounted PC-based HMIs and OITs by hardwired Ethernet links.

PC-based HMIs proved to be a good method for monitoring and controlling plants from the control room and remain the dominant paradigm, but users soon began to demand remote access from areas outside the control room. Installing and maintaining software on PCs located in offices and homes initially accomplished this; however, this became burdensome and expensive.

The next step in remote access solved that problem by using Web browsers to access data from PC-based HMIs and from OITs. This was a tremendous improvement over older methods because software didn’t have to be installed and maintained at each remote access device. Furthermore, it opened remote access to all devices capable of running a browser and connecting to the Internet, primarily smartphones and tablets.

Users were happy with browser-based access until the moment they first used a well-designed app, typically for an everyday interactive task like making a reservation at a restaurant. At that point, they immediately saw the superior power, speed, and ease-of-use of an app as compared to browser-based access-and they began asking for apps for remote access to machines and processes. 

Apps arrive

User demands for apps instead of browser-based access led some HMI and OIT suppliers to develop free or very low-cost apps for customers. These apps provided quick and easy two-way access to screens and data, a big improvement over slow and cumbersome browser-based access (Figure 1).

Unfortunately, most apps were initially limited to one or two device types, typically iPhones and iPads. Apple’s handheld products all use the same operating system, which made app development, testing, and deployment manageable for suppliers.

Other smartphones and tablets, however, have a multitude of different operating systems and screen sizes, which made creating apps for them prohibitively time consuming and expensive. The much larger universe of competing smartphones and tablets based on Android and other operating systems was thus largely excluded.

For example, a company first builds a remote access app for iPhones and iPads. If it wants to include other smartphones and tablets, it must write an app for every brand’s operating system and screen size, typically using a different programming language for each. To port even a simple application from one operating system to another can take developers months, and is often postponed or just not done. Fortunately, a standards-based solution was at hand, namely HTML5.

Standards to the rescue

Figure 2: Using familiar multi-touch technology, operators can troubleshoot and execute commands as much as three times faster than with a single-touch interface. Courtesy: Indusoft, Invensys, and AutomationDirectSearching for a way to speed and standardize app development, HMI software and OIT hardware suppliers turned to HTML5. With HTML5, mobile applications can be as functionally rich and user friendly as the traditional native applications built using Java or C++.

Moreover, HTML5 eliminates the need to create numerous apps because it renders the same user interface correctly sized across multiple formats and operating systems. All users therefore see a similar screen regardless of the device. Better yet from the supplier point of view, HTML5 enables developers to write an application once, then instantly deploy it everywhere. This allows suppliers to quickly deploy new and improved apps to virtually all smartphones and tablets, delivering numerous benefits.

Mobile HMI apps advantages

Mobile HMI applications can offer:

  • Enhanced functionality
  • Ability to easily and quickly retrieve and interact with data
  • Device independence
  • Similar screen experience across multiple platforms
  • Easy navigation methods via multi-touch technology.

Remote access improvements for smartphones and tablets are powering bring your own device (BYOD), a technology implementation that allows employees to use personal handheld devices for work purposes. BYOD can cut costs and improve productivity, but it must include a wide variety of handheld devices to be effective, and the user experience must be first rate. This often means an app is needed, and suppliers are using HTML5 to meet this need. 

Small screens everywhere

As handheld devices become the more common method for remotely retrieving and manipulating HMI and OIT data, the user experience must be geared for these devices. Unfortunately, many current remote access HMI and OIT solutions are still optimized for traditional PC, keyboard, and mouse interaction. These solutions use drop-down menus and commands best accessed via a keyboard and mouse, with remote access from handheld devices somewhat of an afterthought.

To satisfy users and increase productivity, today’s HMI and OIT remote access solutions must instead be developed to work well on platforms ranging from a full-featured PC to a smartphone. These solutions must allow users to manipulate HMI and OIT data as they would with other apps on their devices. To do so, these HMI solutions will have to include optimized screen sizes, different command structures, and multi-touch functionality.

Multi-touch functionality lets users scroll, zoom, expand, and rotate items with familiar smartphone and tablet gestures, such as swipe and pinch. Unlike traditional single-point touchscreens, multi-touch systems recognize the position of several simultaneous touch contacts to perform user-requested actions.

These combinations of touches and finger movements are called gestures. Typical examples of gestures are zoom and pan, which are commonly used to navigate the Web from smartphones and tablet devices. As compared to single-touch, multi-touch enables operators to execute commands as much as three times faster (Figure 2).

Mobile application example

For example, an operator gets a text-message alarm on his smartphone indicating a problem with a particular machine. He quickly presses an app button to fire up the remote access solution. Using multi-touch functionality, he swipes quickly to locate the specific alarm screen related to the machine, instead of using menus to go from screen to screen in a sequential manner.

The operator then uses a two-finger un-pinch gesture to zoom in to the area of interest and quickly determine the exact nature of the problem. He then makes the change required to resolve the issue, all in a matter of seconds.

Of course, similar actions could be performed via a browser with single-point touch. The difference is primarily related to time, but saving time can be of the essence when responding to a problem, and can often make the difference between uninterrupted operation and significant downtime.

The advent of PC-based HMI software and embedded Microsoft Windows OITs lowered the costs of purchasing, deploying, and maintaining an automation system. Their standard protocols and architectures ushered in the era of networked systems and the demise of islands of automation. As Internet technologies and security became more reliable and secure, the demand for remote access grew.

When mobile access was initially offered it was intended for workers using PCs, so the screen sizes and navigation methods were the same as they were for the host system, often a PC-based HMI. However, the expanded capabilities of handheld devices have changed how automation users retrieve and interact with plant data.

Some HMI software and OIT hardware suppliers are embracing this new paradigm by offering solutions that are built from the ground up with the understanding that the number of remote access users with smartphones and tablets will rise exponentially. Remote access capabilities created for handheld devices, often via apps, often have superior functionality compared to browser-based access.

– Marcia Gadbois is vice president of InduSoft, Invensys, and Jeff Payne is automation group product manager of AutomationDirect. Edited by Mark T. Hoske, content manager, CFE Media, Control Engineering,


This Control Engineering online article for April has more information than the print/digital version, with links to related articles below.

Key concepts

  • Human machine interface (HMI) software and operator interface terminal (OIT) hardware deliver remote access.
  • Smartphones, tablets, and other devices benefit from applications optimized beyond a browser.
  • Internet connectivity and mobility can improve overall operations.

Consider this

Could the right information to the right people at the right time improve your productivity and competitiveness?