毕业设计通信专业相关文献翻译.doc

原文：system design for a mini-type remote maintaining terminal device based on a telephone networkabstractthe remote maintaining and diagnosis technology is very important for the distributed and distant on-the-spot equipments and devices for monitoring，predicting，and diagnosing failurethis paper presents a new kind of mini-type remote maintaining terminal devices based on a telephone networkthe system design and implementation is described in detail in the paperthe device is composed of a integrated circuit，telephone dial unit，modulation unit，central processing unit，button input unit and display unitthe mini-type remote maintaining terminal device communicates and exchanges information with the distributed and distant on-the-spot equipments and devices for monitoring, predicting, and diagnosing failurethe data is transmitted through the public switched telephone network (pstn)it can communicate with remote equipments, gather the various parameter data of the devices such as power, power factor, and frequency from the remote industrial equipmentsit can also be used to control the remote devicesin the paper, the hardware and circuit design is described in detailthe device is practically very important for monitoring，predicting，and diagnosing failure with a low total costkeywords：remote data exchange device, pstn, circuit design, dce1introductioninformation communication with remote computers or equipment is of great importance in numerous industrial applications and public data servicesmany kinds of communication and data-transmitting systems have used data communication equipment (dce)to exchange informationthe special-purpose data communication equipment(dce)has a important practical role in those systems, because they are cheaper and more convenient than the systems built up by the computer network to form a distributed environmentthe dce call often satisfy the required special-purpose communication system in many special fieldsa number of experiments and researches have been done regarding the remote data exchange devices in recent yearsmany investigators have explored the special devices that exchange data through public switched telephone networkreddy reported a device that could transmit data over telephone networkshe proposed the basic principles of data transmission over the public switched telephone network (pstn)hong sun investigated a kind of hust-b remote terminal devices, which consisted of computers and measurement devicesit could communicate with remote equipment；gather the parameter data of power, power factor, and frequency from the remote industrial equipmentit could also be used to control the remote devicesshuping mao designed a real-time remote data gathering device based on a neuron chip and network technologieszhiwei jia reported a device that utilized pc isa slotsit realized data exchange between a power system and the remote terminalmachineshui huang suggested a system structure of an internet based radiotherapy diagnose system with some kind of remote devicesalthough many researchers have investigated the remote data exchange system with the special-purpose remote terminal devices，little work has been published on the system and circuit design of the data exchange devices that can transmit the data based on public switched telephone networkin this paper, we investigated a mini-type remote data exchange device that can be used to exchange the data with the remote host computer through pstnthe system principle and the circuit design of the device have been studied in detailthe results of this study may help the design of the pstn based data exchange devices and the system construction of the general used special purposed communicationnetwork2the principle of mini-type remote data exchange devicemini-type remote data exchange devices are considered in a non-industrial fieldthe public has a great demand to exchange data and information with a remote computer and database in daily lifesuch device should satisfy following requirements：1) the data is transmitted through pstn2) the expenses age relative low3)it requires relatively a small size and easy to carry with4)it can be easily operated and managed without certain trainingthe mini-type remote data exchange device is used to exchange data with remote host computers database when data users are dispersed in different geographical positionsusers can set up a connection remote host computer with a mini-type remote data exchange devicethe device can be used at places such as home or a hotel or at any place where pstn exists，to connect the host computers for exchanging through a telephone lineit would improve working efficiency and reduce expensesbecause digital signals are unsuitable to be transmitted in the paired-line of a public switched telephone network, communication between a user and server must be done by using a modem device to modulate the digital signalitu-t has made standards of many kinds of modemsv .34 standards support the speed as 28kpbsthe upgraded edition v.34 v.34 annexes 1201h supports the speeds of 33.6kbps, by using data compression(v.42bis)，the supreme speed can reach 133.8kbpsa new standard is v.90 which can transfer data at 56kbps and a higher rate through data compressionthe mini-type remote data exchange device is used in small and simple terminals that can communicate with the remote host computerone datum server on the host computer and many mini-type remote data exchange devices build up a small-scale communication network and data exchange application systemthe database is in the host computerthe host computer also can communicate with other computers over an internet or intranetthe mini-type remote data exchange devices is used to exchange the data with the host computer through the public switched telephone networksfigure l show the system infrastructurefigure 1: a small-scale communication network and data exchange application system figure 2：the mini-type remote data exchange devicethe mini-type remote data exchange device consists of a number of integrated circuits such as a telephone dial device，modulate integrated circuit, central processing unit, button input device and display devicethe device has many advantages such as small，easy to carry, relatively cheap, easy to operate andlow data transmission costfigure 2 shows the appearance of the device3circuit design of mini-type remote data exchange device3.1 the device infrastructure1)central processing unit：namely cpuit is a single chip micyoco(scm), such as intel 51 scm seriesit is used to control all other components and to coordinate work of all devices2）telephone dial device：it is used to dial and produce dual-tone-multi-frequency (dtmf) signal or pulse signalit is used to choose the datum data exchange server at the remote host computer before setting up a connection with the host computerthis device can be an independent integrated circuit or be included in the following modulation-demodulation device3)modulation-demodulation device：it is used to modulate the digital signals to audio carrier frequency signals for sending to the host computerat the same time it demodulates the audio carrier frequency signals received from the remote host computer through the public switched telephone networks to digital signalsthe demodulated digital signal will be processed by the central processing unit4)the button input device：it consists of a small-scale keyboard and several electronic elementsusers can use the device to input data and operate the mini-type remote data exchange device5)display device：it is used to show the data in the display screenfigure 3: the block-diagram of the circuit3.2 the workflow of the deviceoperators use the button device to input numbers, the central processing unit processes the input data and transmits to the remote host computer through the pstnthe display device shows the data the user inputted and the data received from the remote host computerusers operate the mini-type remote data exchange device by the input devicethe digital signals users inputted will be moderated by a modem and transmitted to the remote host computerthe audio carrier frequency signals received from the host computer will be demodulated by the modem and shown in the display devicethe remote host computer receives requests from the mini-type remote data exchange device and makes corresponding treatments with different application programs，and sends the results back to the mini-type remote data exchange device with the same modulation method through public switched telephone networksthis device uses the back-echo method to confine the data inputted by the userthe modulation demodulation devices receive the demodulation signal and demodulate to the digital signalthe central processing unit reads and deals with data and sends the data to the display device to show the results4conclusionsthis paper presents a new kind of mini-type remote maintain terminal devices based on a telephone network it can be used to transmit data through public switched telephone networksit consists of a small number of integrated circuits, a telephone dial device, a modulation device, a central processing unit， a button input device and a display devicethe device can be used in many applications with the advantagesof a small size，easy to carry, relatively cheap，and easy to operateit is suitable for constructing a mini scale communication network at a low cost for data transmission through the pstn and has extensive application prospectsfurther works should be performed to establish the general mini scale communication network with the host computer and devices through the pstnalso, the communication between the devices should consider the essential function for exchanging information between the device usersfurther research could explore the possibility to design more functions of the data exchange devicesthe pstn based mini type data exchange devices can be used in a wide application filed, such as the stock information querying, the public database and bank account queryingliterature source：college of information technology, zhejiang university of financeeconomics, china 译文：一个基于电话网络的迷你型远程维护终端设备系统的设计摘要远程维护和诊断技术对远距离分布和现场设备的监测、预测和故障诊断是非常重要的。本文提出了一种基于电话网络的新的迷你型远程维护终端装置。本文对该系统的设计和实施进行了详细的说明。 该装置是由一个集成电路，电话拨号装置，调制单元，中央处理单元，按钮输入单元和显示单元组成。迷你型远程维护终端设备运用通信和信息交换及分布式对远处的现场设备进行设备的监测，预测和故障诊断。数据通过公共交换电话网（pstn）传输。它可以与远程设备通信，如功率，功率因数，并从远程工业设备搜集各种频率的器件参数数据。它也可以用来控制远程设备。在本文中，对硬件和电路设计进行了详细说明。该设备实际上对故障的监测，预测和诊断非常重要且总的成本低廉。关键词：远程数据交换设备 ，公共交换电话网络，电路设计，数据通信设备 1 引言远程计算机或设备的信息通信是对许多工业应用和公共数据服务具有重要的意义。多种通讯和数据传输系统使用数据通信设备（dce）进行信息交换。专用的数据通信设备（dce）在这些系统中有一个重要的实际作用，因为它们比在一个分布式环境中建立的计算机网络系统更便宜，更方便。dce调用通常能在在许多特殊领域满足专用通信系统的需要。在近几年许多的实验和研究工作已经完成关于远程数据交换设备。许多学者通过公共交换数据交换电话网络探讨了特殊装置。雷迪报道了一种可以通过电话网络传输的数据的装置。他建议在公共交换电话网（pstn）的基础上进行数据传输。据孙宏报道，一种hust-b远程终端设备，其中包括计算机和测量设备。它可以与远程设备进行通信，收集远程工业设备的功率，功率因数和频率的数据参数。它也可以用来控制远程设备。毛淑萍设计了一个基于神经元芯片和网络技术的实时远程数据采集设备。贾志伟报道称个人电脑设备可利用isa插槽。它实现了电力系统之间的数据和远程终端机器的交流。黄辉提出了一个基于互联网的远程放射治疗某些类型的设备诊断系统的体系结构。虽然许多研究人员调查了远程数据与专用交换系统远程终端设备，些许功能已经被运用到该系统及数据交换设备的电路设计，且能够基于公共交换电话网络进行传输数据。在本论文中，我们调查了迷你型远程数据交换设备，其可以通过pstn和远程主机进行数据交换。该系统原理和设备的电路设计已经被仔细的研究。这项研究结果可能有助于对基于pstn的数据交换设备的设计和一般使用特殊目的的通信网络系统的建设。2 迷你型远程数据交换装置的原理迷你型远程数据交换设备在非工业领域被认可。在日常生活中，公众很想知道数据和信息如何通过远程主机和数据库进行交换。因此设备应满足以下要求：1）可通过pstn传输数据。2）年限的维护费用相对较低。3）它需要相对小的尺寸，易于携带。4）它应该很容易操作，不需要一定的培训管理。当数据用户分散在不同的地理位置，迷你型远程数据交换设备是用来与远程主机的数据库中的数据进行数据交换。用户可以建立一个连接的远程主机一个迷你型远程数据交换设备。该装置可用于如家庭或旅馆或在任何地方的pstn存在的地方，就可以通过一条电话线交换主机电脑。这将提高工作效率，减少开支。 因为数字信号不适合成对的公共交换电话网络，用户和服务器之间的通讯线路传输，必须通过使用一个调制解调器调制数字信号。itu-t已经规定了多种调制解调器的标准。v0.34标准支持的速度为28kpbs。升级后的版本为v.34。v.34附件1201h支持的速度为33.6kbps，通过使用数据压缩（v.42bis），最高速度可达133.8kbps。一个新的标准是v.90，可以传输的数据是56kbps，并且通过数据压缩率较高。迷你型远程数据交换设备是用于小型和简