從結(jié)構(gòu)上來說，實時多任務(wù)操作系統(tǒng)包括兩部分，一部分為操作系統(tǒng)內(nèi)核(kernel)，即實時執(zhí)行程序(Real Time Executive:RTX)，另一部分是輸入輸出部分(I/O)(注意開發(fā)系統(tǒng)不屬于操作系統(tǒng)的范疇)；嵌入式系統(tǒng)對I/O的需求通常比較小(無文件系統(tǒng)需求)，因此很多實時多任務(wù)操作系統(tǒng)本質(zhì)上就是一個實時執(zhí)行程序，如AMX(Kadak)，VRTX(Microtec)，iRMX(Intel)等(這里的X即:eXecutive)，如果純粹從kernel的角度來考察目前流行的各種實時多任務(wù)操作系統(tǒng)的性能，它們的效率差別都不大。
在市面上可以得到一些RTX的源代碼(有用C實現(xiàn)的，有用匯編實現(xiàn)的，還有用PL/M語言實現(xiàn)的)，從internet上也可以蕩一些下來(我介紹一個站點www.eg3.com，堪稱世界電子工程師資源寶庫)，下面我要介紹的一個RTX版本(我命名為SRTX:short RTX)，可以說是RTX中的元老級產(chǎn)品了，來自某研究所，九十年代初他們到美國考察，從美國某公司購得。五年以前，SRTX在國內(nèi)有售，許多搞工控的研究所利用SRTX開發(fā)了一些大型或小型的產(chǎn)品,這里介紹的SRTX我作了一些簡化和改動.
Example to support XML files using MSXML.
=========================================
XML (Extensible Markup Language) is a commonly used basis for representing a
huge range of structured data file formats. The specification is maintained by
the World Wide Web Consortium (W3C?. This plugin is intended as an example of
how XML data can be read with a DataPlugin. You can adjust it to meet the needs
of your own XML file format.
After installing the URI file (double click on it), you can find the VBScript
file located at
"C:\Program Files\National Instruments\Shared\USI\plugins\DataPlugins\XML Example"
You can make changes to this file to read your specific XML file.
This book shows how to design and implement C++ software that is more effective: more likely to behave correctly more robust in the face of exceptions more efficient more portable makes better use of language features adapts to change more gracefully works better in a mixed-language environment is easier to use correctly is harder to use incorrectly. In short, software that s just better.
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％ set some variables in the workspace to control behaviour:
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％ graphicsMode 0 no graphics,
％ 1 graphics, particles, beacons, ground truth
％ 2 graphics, as above + range circles
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％ perfect 0 use beacon range data
％ 1 use ground truth range data
％ clear a
TRAFFIC LIGHT CONTROLLER using C51 and RTX-51 tiny，This program is a simple Traffic Light Controller. Between start time and end time the system controls a traffic light with pedestrian self-service. Outside of this time range the yellow caution lamp is blinking.
This cookbook contains a wealth of solutions to problems that SQL programmers face all the time. Recipes inside range from how to perform simple tasks, like importing external data, to ways of handling issues that are more complicated, like set algebra. Each recipe includes a discussion that explains the logic and concepts underlying the solution. The book covers audit logging, hierarchies, importing data, sets, statistics, temporal data, and data structures.
This program is a simple Traffic Light Controller. Between start time and end time the system controls a traffic light with pedestrian self-service. Outside of this time range the yellow caution lamp is blinking.
16 relay output channels and 16 isolated digital input channels
LED indicators to show activated relays
Jumper selectable Form A/Form B-type relay output channel
Output status read-back
Keep relay output values when hot system reset
High-voltage isolation on input channels(2,500 VDC)
Hi ESD protection(2,00VDC)
High over-voltage protection(70VDC)
Wide input range(10~50VDC)
Interrupt handling capability
High-density DB-62 connector
Board ID
Foreword
The four case studies that follow each have a number of common features. They each illustrate the birth of an idea and show how that idea can be realised into a marketable product. Each case study deals with engineering design and development issues and each highlights the importance of developing sound marketing strategies including market research. The importance of appropriate support mechanisms for young entrepreneurs is also covered. The case studies illustrate how successful entrepreneurs deploy a range of entrepreneurial skills and know-how. Above all, the entrepreneurs are seen to have the capacity to innovate and exercise vision.
We are grateful to Liz Read, Development Manager for Enterprise and Entrepreneurship (Students) at Coventry University for providing these case studies.
