摘要
SWVR—2000型智能综合工程探测仪,是为适应工程勘察领域近年来发展的新方法新技术的需要而研制的,主要用于岩土工程原位测试,混凝土工程强度评价,桩基无损检测以及常时微动监测等方面。数据采集是该仪器的主要部分之一。文中讨论了如何选择A/D转换器,巧妙地利用微机接口的软硬件设计来提高数据采集的速度,给出了数据采集系统的控制策略,最后给出了仪器与系统机联机进行数据通讯的简便方法。
SWVR-2000 Intelligent Engineering Investigation Instrument is a multifunction computer-based investigation system, which is mainly used in the areas of sallow seismic, primary location investigation of the geotechnical engineering, the concrete engineering evaluation, pile base test for engineering architecture and telluric microseism monitoring.The data acquisition is the main part of the instrument. This paper discusses how to improve the sampling speed. If N expresses the numbers of the signal channel, fmax the maximum signal frequence, t the conversion time of A/D converter and T is the sum of all the other time (starting converter, interrupting, fetching, storaging polling and modifying pointers, etc.), according to the sampling theorem and the needs of engineering, the sampling frequence f0 should be:There are some ways to improve sampling speed, one way is to shorten T, another way is to cut downt, still the other way is to increase A/D chips to decrease the numbers of the sampling channels of one A/D converter or to make use of several A/D converters to sample one channel signal in proper order. As T is determined by the hardware and the high speed A/D chip is much higher to the common speed A/D in the market, so that how to use the other ways mentioned above is important and possesses the practical value. This paper discusses the techniques designing the high speed acquisition system by use of common A/D converter(ADC 0804)and gives the details of sampling control tactics of the system. In the last part of the paper, the communicating with IBM PC and its compatible computer is also discussed. The handy way to communicate with other computer is to transmit data with printer interface, which need not to increase any hardware.
关键词
工程勘测
探测仪
数据
采集
通讯
geotechnical investigation, intelligent instrument, data sampling, communication
