If the machine you build requires a graphical operator interface, there's finally a middle ground between a full-blown Windows PC and a proprietary operator interface platform. Vendors are offering an entirely new class of operator interface products based on compact, embedded operating systems such as Windows CE, Windows NT Embedded, and Windows XP Embedded. Embedded operating systems offer high performance and low cost. If your machine requires a graphical operator interface, you'll ultimately have to choose between a full-blown Windows PC and a proprietary operator interface platform. Vendors are offering a completely new generation of operator interface products based on compact embedded operating systems such as Windows CE, Windows NT Embedded, and Windows XP Embedded. These products offer low cost and the compactness of proprietary operator interfaces that are tightly coupled with standard operating systems (OS). These human-machine interfaces seem like the best, and they certainly do, if used in the right application. However, industrial original equipment manufacturers (OEMs) cannot successfully deploy compact embedded operating systems without basic knowledge of embedded systems technology. PCs running Windows desktop operating systems such as NT and XP are sold with the OS pre-installed, but without any operator interface applications. Manufacturers expect OEMs to purchase PCs and then purchase and install the operator interface application software. Proprietary operator interface devices are sold with an OS and operator interface application software pre-installed. Because the OS and operator interface application software are proprietary, modifications to them are either impossible or impractical. It is expected that machine manufacturers have sufficient understanding of the application software to specify, purchase, and configure a suitable proprietary interface. Operator interface devices based on embedded operating systems, like proprietary operator interface devices, are sold with an OS and application software pre-installed. This is because suppliers must customize the embedded operating system before installing the application software. A more detailed explanation of embedded operating systems can be found in the authoritative report by Ralph Damato, Business Manager of Industrial PCs at Xycom Automation: http://www.xycom.com/pdfs/whitepapers/wp-pc-008(d).pdf. Once the supplier develops the customized embedded operating system and downloads it to the hardware platform, the supplier can then download the operator interface application software for production of the final product. Why would industrial OEMs bother purchasing operator interface products based on embedded operating systems? This implies that the instructions for using an operator interface with an embedded operating system are very similar to those required for purchasing proprietary operator interface devices. Machine manufacturers must understand this application and purchase operator interface devices based on this knowledge. Like proprietary operator interface devices, modifying them after purchase is either impossible or impractical. Given such stringent specifications, why would OEMs want to purchase operator interfaces based on embedded operating systems? This is because operator interfaces with embedded operating systems are cheaper, smaller, and more reliable than desktop Windows PCs. In many cases, they can operate without hard drives and their cooling fans. According to one industrial OEM, operator interfaces with embedded operating systems are similar to proprietary operator interfaces, but it is relatively cheaper for suppliers to develop and deploy them. This cheaper development process means that suppliers can provide more features for embedded operating system operator interfaces than for proprietary products. For example, many OEMs want their HMIs to be "web-enabled." Embedded products easily integrate this functionality, but for suppliers, integrating it into proprietary products is quite expensive. Eaton Cutler-Hammer's new PanelMate ePro uses NT Embedded technology for internet connectivity. According to Clyde Thomas, product line manager at Cutler-Hammer, NT Embedded enables the ePro to integrate web-based technology. “OEMs can use the built-in web browser to deliver operating procedures or machine maintenance programs to operators,” Thomas explained. “These programs can be placed on a web server instead of being stored locally on each operator interface unit.” Xycom Automation offers a wide range of Windows CE-based operator interface products. Some of these are bundled with InduSoft Web Studio HMI software. “CE requires minimal resources for processing, so our processing units don’t need hard drives and are low-power, requiring no cooling fans,” Damato said. “CE allows us to easily incorporate advanced features such as USB ports, Ethernet communication, and Windows interfaces.” Rockwell Automation (http://www.rockwellautomation.com) offers RSView Machine Edition, a Windows CE-based machine-grade HMI product specifically designed for OEM machines. It runs on the RAC6182 Windows CE industrial computer. According to Mark Hobbs, product manager for RSView Machine Edition, CE offers more powerful functionality with easier development. CE supports OPC, ActiveX, and terminal services, all of which allow for third-party connectivity, custom development, and distributed HMI functionality.