Embedded Systems Design Europe - November 2007 - (Page 25) RTOS responds with the operator through communication protocols and graphical user interfaces. Because Ethernet is ubiquitous, TCP communication is one of the most important protocols. The RTOS used for the control software must have a robust TCP stack to interface with the outside world. There are many other general embedded interfaces such as USB, Bluetooth, I2C, and SPI that are useful for control systems, but there are also industry-specific interfaces that control systems may need. For example, the aerospace market uses protocols such as ARINC 429 and AFDX; the automotive market uses CAN, LIN, and FlexRay; and the industrial automation market uses DeviceNet, PROFIBUS, and Modbus. Once again, you must be aware of available BSPs and APIs for your RTOS and the amount of development it will take to integrate the specific protocols into your application. While this article examines how to control applications with mostly discrete logic and simple control algorithms. However, in recent years, a new breed of embedded systems called programmable automation controllers (PACs) has combined the features of embedded computing with the rugged reliability of PLCs. From a software perspective, PACs feature real-time platforms with highlevel programming environments that can venture into lower-level coding for more advanced applications. The PACs’ hardware cost is higher per unit than barebones embedded hardware, but the development cost is typically lower and therefore, the time to market is shorter. For high volumes, the custom embedded route is usually the most effective one. When implementing low-volume deployments, however, consider whether a deployable PAC may be a better solution. Gerardo Garcia (gerardo.garcia@ ni.com) is the National Instruments product manager for LabVIEW Real-Time. develop a control system by selecting an RTOS and development tools to create control software from scratch, there’s also an alternative approach. For years, industrial automation engineers have been creating control systems using off-the-shelf programmable logic controllers (PLCs) and modular I/O. Historically, PLCs have been limited to lower-performance Nuremberg, Germany 26 – 28.2.2008 2008 … it´s a smarter world w Register no .de ded-world w.embed ww for your fr ee entrance ticket: Always a step ahead! All the knowledge you need to keep ahead can be found at embedded world in Nuremberg. The latest products and innovative solutions. You just have to be there! Exhibition organizer NürnbergMesse Tel +49 (0) 9 11.86 06-49 12 visitorservice@nuernbergmesse.de Conference organizer DESIGN&ELEKTRONIK Tel +49 (0) 81 21.95-13 40 cgrote@design-elektronik.de Media partners Fachzeitschrift für industrielle Anwender und Entwickler Fachmagazin für Entwicklungen in der Kfz-Elektronik und Telematik Fachmagazin für Entwicklungen funkbasierter Systeme www.embedded.com/europe | embedded systems design europe | NOVEMBER – DECEMBER 2007 25 020-022-024-025_ESDE.indd 25 6/11/07 16:43:19 http://www.embedded-world.de http://www.embedded-world.de http://www.embedded.com/europe
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