Realization of Web-based Control
Once considered impractical for applications requiring responsive animation and real-time control, a new breed of web-based HMI system is starting to appear on plant floors and in manufacturing enterprises. “Java (web) based systems can now deliver sub-second response, rich animation and natural integration with other parts of the corporate information infrastructure,” touts Nathan Boeger of Inductive Automation. Unlike traditional systems, these web-based systems can economically be extended to every aspect of a business such as QC, maintenance, logistics, plant manager, and so forth. Now every participant in the manufacturing cycle can have unprecedented access to vital plant production information.
It's easy to see why web-based systems are gaining popularity. Web-based systems install and run client applications from any web-browser and when users login they always get the most recent version of an application. There are no client licenses manage, no tedious software installations, no application files to copy over and no communication configurations to setup. IT departments are willing to embrace technology they understand. All this is in sharp contrast to traditional systems. The economic advantages of using web-based systems are compelling. The bottom line is, web-based HMIs systems fit well with the rest of the enterprise and facilitate the smooth flow of information throughout an organization without unnecessary difficulty and expense.
When potential users first consider using web-based technology they usually ask about security. Just how secure are web-based systems? The question is especially valid now that post 9/11 committees have deemed HMI and SCADA security “one of the most serious risks to our national security.” Traditional vendors rely heavily on “security by obfuscation” which has never been considered a safe practice. Web-based systems, on the other hand, are already positioned to leverage standard and proven web security techniques as administered by IT departments.
It’s only be a matter of time before legislation mandating minimum HMI and SCADA security requirements will surface. Traditional providers will likely have to overhaul their products to come into compliance. They will welcome this day since they will sell lots of mandated security upgrades.
Seeing What's Next
Functionally speaking, HMIs haven't changed much over the past five years. “HMIs that just do operator interface tasks are a commodity, and you can buy them dirt cheap off the Internet…The real action is in HMIs that provide web access, interface to higher-level enterprise software, perform MES functions”, says Rich Merritt, Senior Technical Editor of Control Global, in his article, “HMI Software is disappearing”.
The book Seeing What’s Next by Christensen, Anthony and Roth, introduces theories to predict major industry changes. These theories are supported with interesting historical examples. Applying these predictive theories to this industry suggests incumbent HMI vendors will continue to service their large existing market without much change. They will probably not compete with their own model. On the other hand, web-based vendors will find success selling where traditional vendors have failed; to those companies who refuse to spend big bucks on systems perceived as being unnecessarily complex, cumbersome and overshooting needs. This is likely to lead to explosive growth for web-based systems in market segments which have been unfulfilled by traditional systems.
Anyone familiar with manufacturing knows the majority of factories barely implement information technology at the plant floor level. There are exceptions, but when you see clipboards being used to record schedules, downtime and production, when you envision how things should be done, you finally come to realize this is a vast untapped market.
There is an accelerating pace of web-based systems being installed in what was essentially a non-consuming market. Users are finally getting what they want – the functionality of an HMI with the economics of a web browser. The real question is not whether web based control systems are an emerging trend – they cannot be stopped, but rather which vendors are poised to jump on the bandwagon and deliver the technology.
This article was written and provided by Steven A. Hechtman, President of Calmetrics Company. Calmetrics is a control system integrator who specialize in efficiency issues and the development of simple, powerful, connected systems. They offer the following services:
- Design and programming of PLC control systems.
- Connecting PLCs to Powerful WebApps and databases.
- Producing clear and concise control system documentation.
- Emergency troubleshooting and support.
- Delivering PLC control and troubleshooting training.
- Advising on potential areas for efficiency improvement.
For more information on Calmetrics, please visit www.calmetrics.com