PACE 60-year Anniversary Series: HMIs and Operator Interfaces
supported by Wonderware
Human-machine interfaces (HMI) have come a long way from the early days of the selector switches and thumbwheelers that assisted the operation of automated manufacturing.
While the next generation of text-based and programmable DOS terminals allowed simple graphical representations of the factory floor, these models still relied on primitive push buttons for operator control.
Through the evolution of the Windows operating system, today’s HMIs and other operator interfaces have been able to evolve in to true clientserver applications, bridging the gap between automation and IT systems.
When Wonderware Australia general manager, Jose Lobato, first entered the industry in the late 1980s, operators were still relying on DOS-based HMIs.
“I first got involved with HMIs in 1989 through propriety-based operator interfaces compatible with specific hardware. These were very limited and clumsy compared to today's products, however they did a very good job at the time,” Lobato told PACE.
Lobato has been involved with a number of leading industrial automation companies during his 25 years in the industry, and has been working with Wonderware products for over 17 years.
For Lobato, the transition to Windows and the networking and security features this allowed has been the biggest development in HMI technology throughout his career.
“This has been Wonderware’s number-one strength; we were the first HMI vendor to supply full HMI products on Windows-based operating systems back in1988. At that time many in our industry laughed at this and predicted that this was never going to be an accepted standard in industrial automation,” Lobato said.
This screenshot shows aspects of a device control HMI display from 2006, controlling a wastewater plant in the United States.
According to Lobato, the scalability, distributed architecture and the flexibility of today's products are a world apart from their predecessors.
“Today's needs are very different and the justification of incorporating HMI and SCADA installations are no longer on the grounds that we saw even five years ago when pretty pictures, number of colours, 3D graphics and many other cosmetics were the key drivers of decision making,” he said.
“Our clients have to remain competitive, reduce waste, increase productivity – let alone efficiency – to stay in business. Our existing and future clientele looks at Wonderware products to achieve return on investment and to demonstrate benefits to business owners and management. Look and feel is important but no one is now assessing our products on these grounds any more.”
Graphics and visualisation
Roy Lumley, a solutions consultant and operator effectiveness discipline lead for a multi-national corporation, has been working in the process industry since 1987.
He is currently engaged in applying industry best practices in data visualisation to improve situational awareness in HMI and alarm management applications at several process sites around the world.
“I started out working in process simulation solutions for operator training; picture a flight simulator for process operators. The experience was both very challenging and very exciting because I was exposed to a wide range of industries and also to a wide range of control systems,” Lumley told PACE.
Screenshot of the SL-GMS HMI from SL Corporation released in 1994, allowing users to operate a process much like playing a video game. (Image courtesy Roy Lumley.)
The earliest graphical HMIs which could be remotely compared to our modern systems was the Yokogawa Centum system, which was followed later by Foxboro's Fox1 and Honeywell's TDC2000.
“These systems were mostly used by oil and gas companies because they were so expensive. ESSO in Altona would likely have been one of the first sites in Australia to have one,” he said.
“My first HMI experience was in 1988 with a SCADA package called Screenware. It was an EGA-resolution, raster-based package which functionally was much like MS-Paint except that you could display values and cause colour changes using floodfills.”
For Lumley, the biggest milestone in HMI technology occurred in the early 1990s when the screens transitioned from low resolution/low colour packages with a few limited functions, to high resolution/high colour, object-oriented packages with full programming capabilities.
“One of the most powerful but simple (and exciting) packages I have ever worked with was SL-GMS. When I was first exposed to this package in 1994 I spent every waking moment of my time for three straight months developing an HMI library that made operating a plant more like playing a video game,” he said.
“I honestly cannot say that I have seen a lot of evolution since that transition in the early 1990s. Most process control HMIs are now object-oriented and support-localised or open programming languages, but very few of the newer features appear to be generations ahead of where we were 20 years ago. In fact, many modern HMIs suffer from performance issues and excessive bugs.”
Modern high-resolution, 4-inch, widescreen colour panels complete with Profinet interface, from Siemens’ Simatic HMI Basic Panels range. One model offers eight tactile function keys as well as an alphanumeric keypad, enabling data entry just like on a mobile phone.
Lumley believes that the shift towards data visualisation has resulted in a step backwards in terms of screen graphics, however these interfaces are safer and more effective for process control operators to use.
“An HMI from 30 years ago was likely 640 x 480 resolution with 16 colours (at best). The graphic objects were often raster/bitmap-based or even constructed using a character or symbol set. Some HMIs were vector-based, but were limited to simple shapes like lines, rectangles, or polygons. The programming environment was highly proprietary and often crude and limited,” he explained.
“A significant shift occurred 20 years ago when HMIs could typically support 1280 x 1024 resolution in (glorious) 24-bit colour. Most HMIs became fully object-oriented and ‘GUI’ became the buzzword of the day.
"Structurally, many packages began to lean more towards open systems like Unix and Windows, and open languages like Visual Basic. Stepping out into a more open environment also allowed the HMI to reach out and manage other applications, or allowed other applications to get access to the HMI.
“The shift in the last 10 years has been less noticeable. Resolution has increased to a typical range of 1920 x 1080 (widescreen) format with 24-bit colour still standard. The trend towards open systems has continued, with HMIs now structured in HTML, Java, .NET, and many tablet and smartphone environments.
"While this trend has provided much more connectivity to the HMI, it has also increased the complexity and – in my experience – reduced the robustness and reliability.”
Connectivity and data
Advantech Australia product sales manager for the industrial automation group, Richard Ronc, says though HMI is a very mature technology, many companies have not updated their systems in years.
“Some clients are using very old legacy equipment from Honeywell, which is at least 20 years old,” he told PACE.
Siemens Simatic HMI software from 2010, designed for efficient and uniform handling of operator control and monitoring tasks.
According to Ronc, who joined Advantech in 2008, the main difference between these legacy systems and more modern offerings is the connectivity and data solutions that current panels offer.
“Previous generations of HMI were obviously lower in processor capability but, with upgrades to computational power processes, new systems are able to be more visually demanding – despite the processes themselves staying relatively the same in terms of computational demand,” he said.
“The previous generation of HMIs may have had a single Ethernet port, whereas now HMIs come with dual Gigabit ports, increasing network capacity by 20 times.
"With USB 2.0 and 3.0 and with up to six ports, there are increases between 45 to 90 times the information flow. There is real hunger for data out there, and current generation equipment now actually has the capacity to capture all of it.”