SCADA systems weave around the web

The Internet is bringing a new lease of life to established Scada (supervisory control and data acquisition) system technologies. Mike Spear reports on new ways of opening up your plant information to a world-wide audience.

The ability to access real-time information from a process, and make it widely and rapidly available beyond the control room, is one of the keys to improving productivity and reducing costs.

According to Marcel van Helten of GE Fanuc, modern Scada/HMI (human machine interface) systems have already created a revolution by streamlining this ability to gather real-time data from the plant and present it as meaningful information for improved management and control. 'But now,' he says, 'with the availability of low-cost but highly effective intranet and Internet web tools, the benefits of direct access to data from Scada/HMI systems can easily be extended to many more users, helping to streamline information even further.'

Using only a PC and a standard web-browser such as Microsoft's Internet Explorer or Netscape's Navigator, any authorised user — internally or externally — can access data on any aspect of a plant's operations. Over the web, it is just as easy to access Scada data from a plant or process on the other side of the world as it is from a plant on the same site. As van Helten says, 'instead of waiting for reports, data from different processes or production lines, and even different plants around the world, can be instantly compared in real time, helping to improve and speed up decision making.'

Scada at your server

GE Fanuc's route to this Holy Grail is the WebView option in its Cimplicity Scada software. This uses 'thin-client' technology, which it says is one of the simplest yet most effective ways of allowing Scada data and process graphics screens to be shared by multiple users on web-browsers. WebView is installed on the web-server and automatically creates a link to a standard HTML page format for direct transmission to the user's PC using a standard browser. All the Scada processing takes place on the web server, so no Scada software has to be installed or maintained on the PC.

WebView is said to be ideal for extending access to Scada information to casual or remote users via local or wide area networks or by direct dial-in. For more dedicated access, or for a larger number of users, GE Fanuc takes a slightly different approach. WebGateway stores pre-prepared HTML pages on the server for instant access by an unlimited number of users. This way, HTML pages can be customised to the end-user's exact requirements, with the likes of point data, dynamic ActiveX objects, set-point buttons and bitmap imports.

At the heart of many companies' web-enabling efforts are the web@aGlance products developed by Intuitive Technology, a company recently acquired by eMation (formerly known as PC Soft; see PE July/August 2000, p9). Web@aGlance software is installed solely on web servers and connects to most major Scada, DCS and historian packages. Although a major player in the Scada market itself, with its Wizcon systems, eMation now finds itself at the hub of many of its former competitors' web-enabling activities. Following a $25million investment from US venture capitalist Patricof, eMation is now purposefully repositioning itself as a 'global Internet technology provider', says business development manager Marcel Laes.

Laes sees the Scada market as fairly mature, with no prospect of the exponential growth of the early days of the technology, and says eMation will slowly move from being a product supplier to one specialising in embedded and web-enabled technologies. With companies such as WonderWare, Intellution, Aspen Technology, Siemens and ABB already using web@aGlance servers to deliver Internet connectivity on many of their systems, eMation has acquired a ready-made customer base on which to build its changing strategy.

This doesn't mean that eMation has moved away completely from products, as the latest release of Wizcon for Windows and Internet demonstrates. Version 7.6 of the company's flagship Scada software is claimed to be the first to incorporate the IEC 61131 programming languages for scripting and macros, adding to the package's existing web publishing facility. Wizcon 7.6 enables users to view, filter and acknowledge real-time and historical alarms from within a browser, so a maintenance or production manager can access alarm information from anywhere at any time.

The latest version of USData's FactoryLink Scada software is now being distributed in the UK by Wizard Information Systems. Developed to run on the Windows 2000 and NT platforms, FactoryLink 7 has many features that are said to contribute to a reduced 'total cost of ownership', such as object-based configuration and the tight integration of Microsoft's SQL Server. It is also said to be the first Scada system to make full use of Microsoft's Windows DNA (Distributed interNet Applications). FactoryLink has also now been bundled with USData's Xfactory product tracking software. 'In the past,' says Ken McDougall, USData's European marketing director, 'large manufacturers with rapid-paced production have had limited options for tracking and monitoring their processes. Many have had to resort to custom in-house solutions to find a system that can keep up with their output... [but] now with Xfactory 1.4 large manufacturers can track even the most demanding processes in real-time while gaining the agility to modify their systems without disruption of their production.'

The latest module in the Xfactory suite is a web-enabled analysis and reporting tool, Analysis. It is said to provide 'enterprise-wide performance visibility, production problem identification and planning facilitation'. What it does is to integrate the supply and demand chains by opening up the shop floor and resource planning requirements to a wider audience.

Scada systems may have reached maturity, but web-enabling them has given an established technology a new lease of life.

Sidebar: Phone home for plant data

Not all remote access to real-time plant data need be done over the web — your mobile phone might do the job. With the IN4MA device from Oakes, for example, users can acquire process data from anywhere within the international GSM network. It uses SMS (short message service) technology to create a link between a mobile phone or PC and process equipment. The user-programmable IN4MA can be set up to send SMS text messages whenever important events occur. Acquiring data from its on-board digital and analogue inputs, it will let the user know when something needs doing — whether they are on the other side of the plant or the other side of the world.

The IN4MA also has outputs that can be driven on and off remotely. So, if an engineer receives an alarm, the outputs could be used to switch to a back-up system, turn systems off or notify a local engineer.

In a similar vein, DASYLab software not only lets users monitor processes on screen, it also signals alerts to predefined events remotely, via networks, the web, email or SMS-enabled mobiles.

Available in the UK from Adept Scientific, DASYLab is basically a 'point-and-click' software package for applications that link sensors and instrumentation to a PC. It needs no programming skills, since configuration is simply a matter of dragging icons into place .