为解决输油管道温度压力参数实时监测的问题，设计了以C8051F930单片机作为控制核心的超低功耗输油管道温度压力远程监测系统。现场仪表使用高精度电桥采集数据，通过433 MHz短距离无线通信网络与远程终端RTU进行通信，RTU通过GPRS网络与PC上位机进行远程数据传输，在上位机中实现数据存储和图形化界面显示，从而实现输油管道温度压力参数的实时监测和异常报警。经实验证明，该系统的12位数据采集精度满足设计要求，漏码率小于1%，正常工作时间超过5个月，能实时有效地监测输油管道的温度压力参数，节省大量人工成本，有效预防管道参数异常造成的经济损失和环境污染。 Abstract: In order to solve the problems on real-time monitoring of pipeline temperature and pressure parameters， the ultra-low power remote pipeline temperature and pressure monitoring system was designed by using the single chip processor C8051F930 as the control core. The high-precision electric bridge was used in field instruments for data collection， the 433MHz short-range wireless communication network was used to make communication between field instrument and RTU， the GPRS was used by the RTU to transmit data to the PC host computer， and the data was stored and displayed in the PC host computer， so the real-time monitoring and exception alerts of pipeline temperature and pressure parameters were achieved. The experiment proves that the system of which error rate is less than 1% over five months working with the 12-bit data acquisition accuracy can effectively monitor the pipeline temperature and pressure parameters in real time， it saves a lot of labor costs and effectively prevents environmental pollution and economic losses caused by abnormal channel parameters.
上传时间： 2013-11-07
上传用户：cuibaigao
Abstract: This application note explains the hardware of different types of 1-Wire® interfaces and software examples adapted to this hardware with a focus on serial ports. Depending on the types of iButtons required for a project and the type of computer to be used, the most economical interface is easily found. The hardware examples shown are basically two different types: 5V general interface and 12V RS-232 interface. Within the 5V group a common printed circuit board could be used for all circuits described. The variations can be achieved by different populations of components. The same principal is used for the 12V RS-232 interface. The population determines if it is a Read all or a Read/Write all type of interface. There are other possible circuit implementations to create a 1-Wire interface. The circuits described in this application note cover many different configurations. For a custom application, one of the described options can be adapted to meet individual needs.
标签： iButtons Reading Writing and
上传时间： 2013-10-29
上传用户：long14578
The standard that governs the design of avioniccomponents and systems, DO-254, is one of the mostpoorly understood but widely applicable standardsin the avionic industry. While information on thegeneral aspects of the standard is easy to obtain, thedetails of exactly how to implement the standard aresketchy. And once an entity develops a process thatachieves compliance, the details of how compliancewas achieved become part of the intellectualproperty of that entity. This white paper focuses onthe details of developing a DO-254 compliantprocess for the design of FPGAs.
上传时间： 2013-11-12
上传用户：q123321
According to CIBC World Markets, Equity Research, theFlat Panel Display (FPD) industry has achieved sufficientcritical mass for its growth to explode. Thus, it can nowattract the right blend of capital investments and R&Dresources to drive technical innovation toward continuousimprovement in view quality, manufacturing efficiency,and system integration. These in turn are sustainingconsumer interest, penetration, revenue growth, and thepotential for increasing long-term profitability for industryparticipants. CIBC believes that three essential conditionsare now converging to drive the market forward
上传时间： 2013-10-18
上传用户：日光微澜
Abstract: High-performance base-station (BTS) receivers must meet half-IF spurious requirements, whichcan be achieved by using the proper RF mixer. To help engineers, this application note illustrates the
上传时间： 2013-10-17
上传用户：daoxiang126
同步技术是跳频通信系统的关键技术之一，尤其是在快速跳频通信系统中，常规跳频通信通过同步字头携带相关码的方法来实现同步，但对于快跳频来说，由于是一跳或者多跳传输一个调制符号，难以携带相关码。对此引入双跳频图案方法，提出了一种适用于快速跳频通信系统的同步方案。采用短码携带同步信息，克服了快速跳频难以携带相关码的困难。分析了同步性能，仿真结果表明该方案同步时间短、虚警概率低、捕获概率高，同步性能可靠。 Abstract: Synchronization is one of the key techniques to frequency-hopping communication system， especially in the fast frequency hopping communication system. In conventional frequency hopping communication systems， synchronization can be achieved by synchronization-head which can be used to carry the synchronization information， but for the fast frequency hopping， Because modulation symbol is transmitted by per hop or multi-hop， it is difficult to carry the correlation code. For the limitation of fast frequency hopping in carrying correlation code， a fast frequency-hopping synchronization scheme with two hopping patterns is proposed. The synchronization information is carried by short code， which overcomes the difficulty of correlation code transmission in fast frequency-hopping. The performance of the scheme is analyzed， and simulation results show that the scheme has the advantages of shorter synchronization time， lower probability of false alarm， higher probability of capture and more reliable of synchronization.
上传时间： 2013-11-23
上传用户：mpquest
The standard that governs the design of avioniccomponents and systems, DO-254, is one of the mostpoorly understood but widely applicable standardsin the avionic industry. While information on thegeneral aspects of the standard is easy to obtain, thedetails of exactly how to implement the standard aresketchy. And once an entity develops a process thatachieves compliance, the details of how compliancewas achieved become part of the intellectualproperty of that entity. This white paper focuses onthe details of developing a DO-254 compliantprocess for the design of FPGAs.
上传时间： 2013-11-03
上传用户：ysystc670
According to CIBC World Markets, Equity Research, theFlat Panel Display (FPD) industry has achieved sufficientcritical mass for its growth to explode. Thus, it can nowattract the right blend of capital investments and R&Dresources to drive technical innovation toward continuousimprovement in view quality, manufacturing efficiency,and system integration. These in turn are sustainingconsumer interest, penetration, revenue growth, and thepotential for increasing long-term profitability for industryparticipants. CIBC believes that three essential conditionsare now converging to drive the market forward
上传时间： 2015-01-02
上传用户：小枫残月
This paper addresses the issues relating to the enforcement of robust stability when implementing the Adaptive Inverse Control (AIC) scheme. In this scheme, an adaptive FIR filter is added to a closed-loop system in order to reduce the output error caused by external disturbances, enhancing the performance achieved by linear time-invariant controllers alone.
标签： implementing enforcement addresses the
上传时间： 2013-12-23
上传用户：佳期如梦
Linux in a Nutshell, 5th Edition By Stephen Figgins, Robert Love, Arnold Robbins, Ellen Siever, Aaron Weber ... ... ... ... ... ... ... ..... Publisher: O Reilly Pub Date: July 2005 ISBN: 0-596-00930-5 Pages: 944 Over the last few years, Linux has grown both as an operating system and a tool for personal and business use. Simultaneously becoming more user friendly and more powerful as a back-end system, Linux has achieved new plateaus: the newer filesystems have solidified, new commands and tools have appeared and become standard, and the desktop--including new desktop environments--have proved to be viable, stable, and readily accessible to even those who don t consider themselves computer gurus.
标签： Nutshell Edition Figgins Stephen
上传时间： 2015-12-03
上传用户：frank1234
