It seems that this story has fueled part of the markets fears about Wind Rivers future market share. This is from Control Magazine.
CE: The Coming Era
Riding on the Shoulders of Its Big Brother NT, Windows CE Is Bringing New Levels of Connectivity, Integration, and Interaction to the Plant Floor
By Bob Waterbury, Senior Editor
Windows CE is popping up everywhere--in palmtop and handheld PCs, mobile communications systems, television set-top devices, and vehicle information systems. It is also coming to a plant floor near you in the form of operator interfaces, controls, embedded intelligence, and mobile operation/maintenance diagnostic devices.
"CE fulfills the vision of information at your fingertips," said Bill Gates, CEO of Redmond, Wash.-based Microsoft. "People want and need information on a small device, in their car, on their cellular phone, wherever they go." Microsoft is committed to providing that productivity, mobility, and ease of use, and is extending its vision to the plant floor. Moreover, CE will offer access to wireless data in a familiar, user-friendly package.
Operating on a handheld PC, for instance, Windows CE has a look and feel familiar to Windows 95/98/NT users. It offers many of the same icons and applications. But CE is not simply the Toys ‘R' Us version of Microsoft's bigger siblings. It features a subset of other Windows functions, yet it is not just a stripped, scaled-down version.
Inside Windows CE
Microsoft developed Windows CE from the ground up as a small-footprint, modular, customizable operating system based on the Win32 API (application programming interface) for embedded systems. It provides a software foundation that can be used to assemble numerous devices in various configurations. The handheld PC is one such device. Other platforms include point-of-sale terminals, medical diagnostic systems, navigation systems, mobile communication devices--and industrial controls.
Windows CE features a rugged, diskless operating system that does not have to be rebooted every time it is used. In fact, a CE handheld or palm-size PC can be configured to turn on instantly in response to a keystroke, stylus screen tap, or voice command.
Underneath the familiar interface, the CE operating system is quite different from other Windows software. It is customized to run on a variety of processors. This means that normal desktop PC applications are not directly portable to CE devices. In addition, it does not offer a DOS window, further eliminating transference of such applications.
CE is "a 32-bit, multitasking, multithreaded open operating system supporting embedded, mobile, and multimedia applications," says Dave Rohn, product development manager, open controls business, Rockwell Automation, Cleveland. "It allows PC and non-PC devices [Figure 1] to share information, communicate with one another, and connect to the Web. But their applications are not automatically portable across different types of devices."
CE will run two or more applications simultaneously. It is fully Win32-compatible except that it does not offer all of the extensions such as OLE, DDE, and so forth. Compared to the memory and storage needs of Windows 95/98/NT, CE requires only a small fraction of those capabilities. The entire operating system fits into less than 0.5 MB of ROM, and requires only about 200 kB of RAM. The small memory and storage footprint makes CE very attractive to embedded systems developers.
COMING TO A PLANT NEAR YOU?
PC-based control systems such as this application at Kwikset Corp.,
Waynesboro, Ga., are using Windows CE in multiple hardware
platforms to provide connectivity.
Current versions of Windows CE are not true real-time operating systems, but they offer very good support for most embedded system applications. They run in a fully preemptive multitasking environment in fully protected memory spaces. But version 3.0, due for release in late 1999, is scheduled to offer true real-time capabilities for plant floor applications (see sidebar).
"Our current CE products operate at 10 ms, which is faster--more real-time--than some proprietary real-time systems operating on the plant floor now," says Larry Ricci, general manager of industrial platform development, Total Control Products, Melrose Park, Ill., an operating unit of GE Fanuc. "If greater speed and determinism are required to handle something like bottle counts coming off a high-speed filling line, then all you have to do is add a smart card. Many of today's PLCs operate no faster than 20 ms, and they're considered real-time." That issue should be resolved once and for all with the release of V. 3.0.
CE Building Blocks
The Windows CE software cannot be purchased and installed by users. It comes pre-installed on supplier devices. Part of the reason for that is the need for device and processor customization. "Vendors can select from 40 different CE components," says Rohn. "An almost infinite number of CE variations is possible, according to the requirements of the device and its application." Each software installation must be customized to the hardware requirements.
Embedded system designers can develop applications code for a Windows CE platform in a fairly straightforward manner. It can be accomplished on a Windows NT platform using Microsoft's Visual C++ for Windows CE, MS Visual Basic, or the new Windows CE Platform Builder from Microsoft. According to Microsoft, a minimal operating system could be built using nothing more than the kernel and real-time clock; a full operating system would add communications protocols, file system, [spell out]GDI, and user interfaces.
The use of different processors is another complicating issue. Windows CE currently operates on three major processors, and is compatible with additional RISC, 486, and 586 processors. Vendors incorporating CE into their products can choose from the x86, MIPS, and SH3 product families based on cost, performance, personal experiences, and preferences. Arnold Estep, marketing director, Quantum Effect Design, Santa Clara, Calif., says that the best microprocessor architecture is one that provides the highest utilization of the hardware resources. Since unused transistors consume both power and real estate, the best price-performance is achieved by selecting a processor architecture designed for overall efficiency.
Al Chisholm, chief technical officer, Intellution, Naperville, Ill., also points out that "Windows CE is a ‘Windows-like' operating system. It is similar to Windows NT, for instance, but some things work the same, others are missing, new things are added, and a few things simply behave differently. In relation to OPC [OLE for Process Control and Factory Automation], for instance, there is no DCOM [Distributed Common Object Model] support built into CE at this time. This means that only in-process servers will work on standard Windows CE.
MAKING REAL-TIME CE
Real-time determinism allows users to rely on their operating system to respond to a critical event within a prescribed time limit. This time limit varies with the application and system throughput, so developers need information about the system interrupt model, driver model, scheduler capabilities, bounded time limits for operating system calls, and memory management.
Experts at Austin, Texas-based National Instruments explain that when an interrupt (IRQ) is detected in current versions of Windows CE, an interrupt service routine (ISR) is called that determines which interrupt service thread (IST) should be started. The IST runs the associated interrupt function. Upper bounds on the time it takes to execute ISRs and ISTs can be set, and thus establish interrupt latencies. In fast real-time systems, however, CE will encounter problems because when an ISR is called, it blocks IRQs. Also, current CE systems have only eight priority levels. Most real-time operating systems have 24-256 priority levels.
Because Windows CE is a 32-bit multitasking operating system, it allows up to 32 processes to run simultaneously. Each process has one or more threads that operate on a priority basis. Threads run until finished, and therefore can produce an interrupt latency. Windows CE 3.0 is targeting sub-50-microsecond thread latencies on typical processors. It also promises more than eight priority levels, but the exact number is not known at this time. Version 3.0 is likewise scheduled to offer a nested interrupt capability that allows a higher priority ISR to interrupt a lower level one.
Component Categories, built into newer OPC servers to allow clients to browse for available servers, is also missing from CE currently, along with several other widely accepted OPC features." This may change, however, with coming releases of Windows CE.
Platform Proliferation
Windows CE was designed to perform as an embedded system. It is a small, scalable software system that operates in a broad range of products including terminals, computers, controllers, and communications devices. For that reason, it likely will be used in hardware platforms spanning a wide variety of industrial, commercial, and even military applications.
"Right now, Windows CE is positioned in three major industrial application areas," says Russ Agrusa, president, Iconics, Foxborough, Mass. "These include combination computer and flat panel operator interfaces, smart device embedded controls, and mobile computing/diagnostic devices. The CE rationale is pretty much the same in each case: diskless operation (no rotating parts), instant-on, solid-state construction, mission-critical reliability, and the promise of real-time determinism."
Companies such as Xycom, Nematron, and Ann Arbor Computers are actively implementing CE in their operator interface, terminal, and control products, according to Agrusa. Embedded CE is being used in all types of control products including loop, chart, and temperature recorders--not to mention the "soft" control products that compete in the PLC arena. Agrusa cites Foxboro, Siebe, Eurotherm, Siemens, and others that are active in the embedded controls area.
For handheld and palm-size computer applications, industrial CE products are being developed to run on commercial devices manufactured and marketed by Hewlett-Packard, Sharp, Casio, Compaq, Philips, and others. Such mobile applications will likely include alarming, trending, data logging, and operation/maintenance diagnostics. According to Agrusa, these devices are ideal for CE applications because, in addition to the normal CE benefits, they feature wireless Ethernet for remote access, low power consumption, and integration with existing systems via OPC servers.
Though not directly in the industrial domain, other interesting CE platforms include advanced mobile communications devices such as pagers and digital cell phones. These will offer wireless Web access allowing users to view e-mail, check out abbreviated Web sites, engage in electronic commerce, access corporate intranet data, and obtain news, weather, and traffic reports. Putting this innovation in perspective, Chuck Parrish, executive vice president, Unwired Planet, Redwood Shores, Calif., says "It is the surgical extraction of the key information I want." At some point, integration of this wireless CE technology into devices for industrial process control may become commonplace as well.
A CE-based auto PC also is being developed that will provide trip, operation, and positioning data for vehicles. This effort is sponsored by the automotive/transportation industry as a means to provide integrated sound and controls using voice technology.
The Changing Process LANscape
Only a few years ago, PLC manufacturers were arguing that PC control on the plant floor was an unworkable idea. Their protests were aimed at protecting valuable hardware investments as well as lucrative proprietary software products. Inevitably, PC modules were introduced into high-end PLC products. The market was further opened up to PC control with the introduction of Windows NT 4.0 and real-time extensions that followed.
Poised to capture the real-time embedded device market, Windows CE now may become the NT companion operating system of choice for the plant floor. It is, after all, part of the Windows family, uses many of the same programming and development tools, looks and feels similar, offers users a familiar set of operating instructions, and promises sufficiently real-time performance for most batch and process control applications. For these reasons, CE is being incorporated into PLCs, operator interfaces, supervisory control and data acquisition (SCADA) systems, and embedded controls for various smart devices.
"We see great potential for CE in embedded systems for controlling valves, motors, and other dedicated smart devices," says Don Holley, industry automation marketing manager, National Instruments, Austin, Texas. "In PC soft control, CE is an excellent real-time alternative to NT and proprietary operating systems. Built-in connectivity through OPC is one factor that is driving the development of CE applications. Its small footprint is another major factor in standard platform selection."
"Java is a mature operating system that is competitive with--or possibly complementary to--Windows CE," says Hesh Kagan, director of development, Siebe Industrial Automation, Foxboro, Mass. "But I doubt that Sun Microsystems and other Java backers have the marketing muscle to head off CE in the industrial marketplace. CE seems to have a lock on new embedded control applications because of its ties with the Microsoft Windows COM, DCOM, OPC strategy. If the embedded CE footprint can be reduced to less than 1MB, or even 500k, that will be key."
"Microsoft has 600 software developers working exclusively on Windows CE right now," says Agrusa. "They're committed to CE, and are working hard to reduce the footprint. CE won't hurt its existing NT business because it fills a complementary supporting role on the plant floor."
Windows CE also has helped spawn new strategies for plant-floor information distribution. "By adopting CE at the cell level, multi-client, multi-server applications can unify the enterprise without the usual filters or information bottlenecks," says Ricci. "Total Control Products is using CE to invert the information pyramid, allowing devices to publish and deliver data to distributed client applications anywhere in the enterprise--to become a Web server to the Internet [Figure 2]. When OEMs begin embedding CE on smart devices such as packaging machines and textile looms, things will get even more interesting as the machines themselves become targets for real-time applications software."
CE Market Knowledge, Acceptance
"The PC-based soft control business is rapidly becoming CE control," says Paul Camuti, general manager of industrial software business, Siemens, Princeton, N.J. "But a certain amount of education still needs to be done. Industrial users recognize the fact that they may have Pocket Excel and similar programs on their personal handheld PC, but they still don't see the connection to their work on the factory floor [Figure 3]. Likewise, the vertical markets need to be educated about the benefits of CE in a distributed information environment."
"Users and distributors are generally wary of Windows CE," says Rohn, "because in many cases it means converting from eight or 16-bit processing to a full 32-bit processing environment. Systems integrators, on the other hand, love it, because it offers another means of opening up the plant floor environment. In the next year or so, Rockwell Automation will be able to run a complete software control system on a Windows CE platform. This will require taking proprietary design conventions and opening them up to CE. We are developing both a CE software control system and an operator interface platform that can be used in a hardened, bolted-down configuration. This allows plant floor personnel to monitor the operation and maintenance of industrial automation systems first-hand."
"The things holding back Windows CE right now are the relative immaturity of the technology, the lack of applications software, and the size of the footprint--which is still too large to be embedded on some small devices," says Jim Balent, real-time senior product marketing manager, National Instruments. "The real-time issue is being addressed and should be resolved by the end of this year."
PROCESS APPLICATIONS
Operating on Windows CE platform allows the behavior of a PLC with
the openness of a PC, all in a standard operator panel format.
"Realistically, a footprint in the order of 100 kB is required in order to embed CE on certain smart devices such as valves and transmitters," says Rohn. "But if you reduce the footprint by eliminating COM, DCOM, Ethernet, and HTML," says Ricci, "you risk stripping it of everything that sets it apart from existing proprietary solutions."
Camuti says, "Microsoft is committed to getting down onto the plant floor, but it will require changes in the way it normally does business. They can't release something prematurely and then send out service packs two months later to fix bugs in the OS. Industry users won't stand for it. They won't tolerate using flash ROM to periodically upgrade their OS."
Rosy Outlook
In spite of some unresolved issues and unanswered questions, there is great enthusiasm for Windows CE in process control.
Automation Research Corp. (ARC), Dedham, Mass., summarizes a recent study report by stating, "Windows CE promises to unify the embedded and low-end controller market as a platform complementary to NT-based master controllers in all control type segments."
"We feel CE will replace most of the HMI products on today's plant floor," says Ricci. "It is far more rugged, crash-resistant, and dependable than anything else on the market. Furthermore, it allows us to change how information is published, broadcast, and applied in the production environment."
"When all is said and done, embedded CE will be as prevalent as cockroaches on the plant floor," says Agrusa, "it'll be everywhere!"
(Real-Time sidebar with diagram)
Making Real-Time CE Reality
Real-time determinism allows users to rely on their operating system to respond to a critical event within a prescribed time limit. This time limit varies with the application and system throughput, so developers need information about the system interrupt model, driver model, scheduler capabilities, bounded time limits for operating system calls, and memory management.
Experts at Austin, Texas-based National Instruments explain that when an interrupt (IRQ) is detected in current versions of Windows CE, an interrupt service routine (ISR) is called that determines which interrupt service thread (IST) should be started. The IST runs the associated interrupt function. Upper bounds on the time it takes to execute ISRs and ISTs can be set, and thus establish interrupt latencies. In fast real-time systems, however, CE will encounter problems because when an ISR is called, it blocks IRQs. Also, current CE systems have only eight priority levels. Most real-time operating systems have 24-256 priority levels.
Because Windows CE is a 32-bit multitasking OS, it allows up to 32 processes to run simultaneously. Each process has one or more threads that operate on a priority basis. Threads run until finished, and therefore can produce an interrupt latency. Windows CE 3.0 is targeting sub-50-microsecond thread latencies on typical processors. It also promises more than eight priority levels, but the exact number is not known at this time. V. 3.0 is likewise scheduled to offer a nested interrupt capability that allows a higher priority ISR to interrupt a lower level one.
(captions)
Figure 1: [Head to come]
PC-based control systems such as this application at Kwikset Corp., Waynesboro, Ga., are focusing on the use of Windows CE in multiple hardware platforms. (Photo courtesy of Rockwell Automation)
Figure 2: [Head to come]
Diskless client computer delivers Windows CE to the factory floor with touchscreen operator interface. (Photo courtesy of Total Control Products)
Figure 3: [Head to come]
Operating on Windows CE platform, the Simatic MP270 Multi Panel combines the behavior of a PLC with the openness of a PC, all in a standard operator panel format. (Photo courtesy of Siemens Industrial Automation)
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