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.
Manufacturers 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.
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.