Web-based HMIs transforming visualization and data-sharing on factory floors

"The intersection of technology and people ?whether it抯 as simple as the grip on a hand tool or as complex as the entire network infrastructure for a major, global manufacturer ?is called the human-machine interface (HMI). Highly advanced HMI systems for data-sharing, such as email, project management software and instant messaging, have been used by the front offices of most companies for years, while their factory floor lagged behind. That抯 changing, thanks to recent advances in web-based HMI technology, including the use of industrial touch-screen computers.
Data-sharing in manufacturing has come a long way from clipboards and manual relays. Factories have implemented forms of computerized human-machine interfaces but the majority of those HMI and SCADA (supervisory control and data acquisition) systems are standalone applications using outdated technologies such as HTML and screen-scraping. These technologies have improved data sharing by offering remote monitoring but they抮e severely limited in their ability to provide real-time info.
Limitations of HTML and Screen-Scraping
HTML displays static pages in a common language that any browser can translate. While this technology is fine for viewing static pages of data, it can抰 show rapidly changing data or provide real-time control of a machine. Because update rates are infrequent, using HTML for data-sharing is not a viable option for applications requiring alarm notifications, constant data monitoring or interactive animations.
Remote monitoring and machine control can also be achieved through screen-scraping, one of the most common HMI approaches in use today. Screen-scraping is exactly what it sounds like: 搒craping?the image from a server抯 screen and transferring it to the client/user. The client machine then displays the server抯 screen image and transfers its own user input to the server, allowing the operator to interact with the machine as if he were in front of it.
Screen-scraping does allow for remote access, but not real-time data sharing. Due to the amount of data being transferred, effective screen-scraping requires high-speed connections and a limited number of users. It also requires that the screen be resent every time to update any changes. In addition, the server and all clients must display the same screen data. Different operators cannot look at different data or interact using a different language.
New Web-Based HMIs Offer Real-Time Data Sharing and Remote Access
Newer web-based HMI systems are changing all that. Applications featuring Ajax, Flash, Microsoft.net and Java programming are revolutionizing visualization on the factory floor and giving operators and executives the power to:
?Share real-time data
?View several machines from a single location
?Share information up and down the enterprise ― from the executive suite to the plant, and from the factory floor to the top floor.
New HMI tools enable companies to share real-time data effectively. The business office can get plant metrics, such as production rates, and even check on a machine抯 condition from their desktop PC. Plant operators can check on data through industrial touch-screen computers on the factory floor, or on the go from their PDAs and mobile devices. Maintenance people get alerts from web browsers that can access the data from anywhere. And manufacturers and process plants can share data across multiple facilities.
This level of real-time data-sharing offers serious benefits for companies as a whole, including the availability of vital information getting to key decision makers in every part of the organization. New HMI applications are bringing the same productivity improvements seen in the business world to the factory floor.

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