23 April 2001
Factory floor gets leaner through thin clients
Since Industrial Computing published its first thin-client technology article over a year ago, that technology has significantly advancedóbut what will 2001 hold for thin clients and the industrial market?
Indications are that more companies will turn their operator interfaces (OIs) over to thin clients and the technology will find broad acceptance.
Two factors support that. One, thin clients address many of the problems that currently exist with running PCs on the factory floor. Two, they don't demand changes in either plant software or interface screens.
Thin Means What?
Thin clients allow users to run standard MS Windows-based applications under the mainframe-computing model and minimize complexity by simplifying long-term maintenance.
But the real savings come from the centralized computing model, where software loads and run on a single machine.
Moving programs to the server, called a Terminal Server in a thin-client system, dictates simpler clients by eliminating components prone to failure such as disk drives and scaling back parts like memory required for a traditional PC.
On top of this thinócut-downóhardware, a minimal operating system (OS) is loaded with just enough power to drive the client's graphics card, some I/O, and an Ethernet port.
Resulting is a streamlined thin client that delivers the user interface at the control point(s) for the process, while keeping the applications locked up in a secure computer room.
Going back to the mainframe model, the Windows Terminal Server functions as the mainframe; these scaled-down clients become the terminals.The client handles all user interfaces, displaying graphics and getting user input via the keyboard and mouse/touchscreen. By offloading most of the processing to the server, it easily handles all tasks with its limited hardware compliment. Its well-defined requirements don't increase even if the user loads a more complex software package. This means that the thin client hardware will not grow obsolete for many years.
The server, which runs up to 25 instances of even large OI programs (Wonderware comes to mind), is not anything special. Hardware technology has far outstripped demands of the OS and any of its programs. Applications that give the processor a workout only do so for short bursts, meaning there are still plenty of spare cycles.
Off To a Slow Start
The technology first had to demonstrate it could be trusted with the responsibility of keeping a manufacturing operation going. It also had to be well understood and accepted by plant management and equipment providers alike.
Another implementation hindrance was the fact that the thin client was designed to replace the PC, where companies have been running fairly complex OI programs for a decade or more. Operators demanded these same applications but software companies were not yet ready to step out and say their software would run reliably on a thin-client platform. Running these large applications once on a machine was a challengeónobody could even guess at possible interactions once these same programs were loaded ten to twenty times on the same PC.
The difficulty of setting up the Windows server adds to these problems. When Microsoft originally released a Terminal Server platform for Windows, it was as an afterthought to NT 4.0. Released without much fanfare and amid a good bit of confusion, the productóofficially called NT 4.0 Terminal Server Edition (TSE)ówas difficult to install and configure.
The Terminal Server portion that was required to support multiple instances of an application running on a single machine was not just a patch that could be loaded onto a standard NT 4.0 Server. It, NT 4.0 TSE, was a complete OS that had to be loaded from scratch, and loaded by the user because servers could not be ordered with NT 4.0 TSE preloaded. This made it very difficult for users to play around with thin clients.
Growing Through Last YearThe rise in industrial thin-client installations and most of the factors contributing to their popularity has been, however, a direct result of last year's events.
Perhaps the single biggest factor is major industrial applications supported on a Terminal Server platform. While companies like InduSoft and Ci Technologies have had a thin-client-ready product that for quite some time, Wonderware was the first major company to throw its hat into the Terminal Server ring. In mid-2000, they released a product designed to work with Windows 2000 Server. Intellution followed in early 2001with a similar product. Now a user can install any of these packages on a Terminal Server system and expect to get help from the software company.
Then there was also adoption of Windows 2000 Server. Microsoft's NT 4.0 TSE seemed like an afterthought but Microsoft felt strongly enough about thin client technology to embed it into every version of Windows 2000 Server. This increased not only Terminal Server popularity but also its availability. Now, any company that has a standard Windows 2000 server also has a Windows Terminal Server. By simply loading a thin client session on their existing Windows NT or 9x OSs, companies can run a thin-client system with minimum expense, effort, or risk.
There was also adoption of thin-client technology commercially. Estimates for year 2000 thin client sales are about $1.2 million, which is double 1999's and quadruple 1998's. This growth has resulted in an increased awareness of thin-client technology among those most directly involved in computer technology, the IT department. Now, it is not uncommon for someone in IT to suggest thin clients when decision makers have meetings about a factory's new or updated user interface system.
Finally, more companies sold and advertised the product. As user demand for this technology has increased, so has the number of hardware or software companies promoting thin-client technology.
All these activities, coupled with the acceptance of Windows 2000, make the future look very bright for industrial thin clients. IC
David Hancock is a vice president of Automated Control Products. Reach him c/o editors at IC@isa.org