【正文】 ，包括10個(gè)數(shù)字鍵和“數(shù)據(jù)收集“鍵，”Enter“鍵，”復(fù)位“鍵。采用了相反的方向連接方法，PB口和8155 PC端口（2）連接到鍵盤(pán)的行電路與列電路分別。串行通信模塊在圖9的左側(cè)部分所示，微控制器的信號(hào)傳輸由RS485到主機(jī)計(jì)算機(jī)地上，并且MAX485是用于將電壓轉(zhuǎn)換。 RS485是一種多點(diǎn)雙向半雙工通信基于高噪聲抑制功能的單平衡線電路上的陽(yáng)離子鏈接，傳輸速率高，傳輸距離長(zhǎng)和寬共模范圍，其最大傳輸速率達(dá)10Mbps的最大電纜長(zhǎng)度達(dá)到1200米。P21和AT89S52的P10將帶聲光報(bào)警裝置時(shí)的控制，甲烷氣體濃度的測(cè)試值超過(guò)預(yù)設(shè)值。4控制系統(tǒng)的軟件設(shè)計(jì)軟件控制系統(tǒng)的主要功能，包括系統(tǒng)初始化，閾值設(shè)定，甲烷氣體濃度數(shù)據(jù)采集和顯示，串行通信等方式來(lái)實(shí)現(xiàn)上述功能，我們開(kāi)發(fā)了系列親使用51單片機(jī)的連續(xù)組裝克包括主程序語(yǔ)言程序，鍵盤(pán)掃描程序，A / D轉(zhuǎn)換程序，報(bào)警程序，串行通信程序，數(shù)據(jù)顯示程序，系統(tǒng)診斷驚人程序，雙字節(jié)乘法程序，三字節(jié)的二進(jìn)制編碼的十進(jìn)制程序和看狗程序。該系統(tǒng)是由許多模塊，由于我們引入有限的空間只有主程序。主程序的流程圖在圖10中示出第一，主程序初始化單片微型計(jì)算機(jī)寄存器和I / O端口，然后，看掃描鍵盤(pán)如果數(shù)據(jù)收集鍵被按下，如果沒(méi)有，保持掃描鍵盤(pán)，直到數(shù)據(jù)采集鍵被按下。當(dāng)收集鍵被按下時(shí)，如果用戶(hù)要復(fù)位門(mén)限值，只要按下調(diào)節(jié)值鍵設(shè)置新的值，然后按ENTER鍵完成這一步。當(dāng)輸入鍵被按下時(shí)，系統(tǒng)開(kāi)始數(shù)據(jù)協(xié)作的操作經(jīng)文和A / D轉(zhuǎn)換，然后將轉(zhuǎn)換后的數(shù)據(jù)發(fā)送到由二進(jìn)制格式調(diào)用雙字節(jié)乘法子程序。我們需要三個(gè)存儲(chǔ)單元持有這些數(shù)據(jù)，因?yàn)樗鼈冊(cè)诙M(jìn)制格式的24位數(shù)據(jù)。接著，系統(tǒng)會(huì)發(fā)送這些二進(jìn)制格式數(shù)據(jù)轉(zhuǎn)換成二進(jìn)制編碼的十進(jìn)制格式通過(guò)調(diào)用子程序三字節(jié)的二進(jìn)制編碼的十進(jìn)制。在最后一步，在比較與預(yù)先設(shè)定的值閾值，以決定是否該系統(tǒng)應(yīng)發(fā)出報(bào)警信號(hào)。在此期間，這些數(shù)據(jù)將被發(fā)送通過(guò)RS485串行主辦地上的計(jì)算機(jī)通信單元。靜止時(shí)。單片機(jī)的晶體振蕩器頻率在本系統(tǒng)中采用為12MHz，具有定時(shí)器/計(jì)數(shù)器，模式1的工作（16位定時(shí)器/計(jì)數(shù)器），其MAX進(jìn)制時(shí)間間隔約為66ms，所以系統(tǒng)會(huì)發(fā)送一個(gè)飼養(yǎng)狗的信號(hào)看門(mén)狗電路每66ms。附錄4 外文參考文獻(xiàn)（原文）Research of Intelligent Gas Detecting Systemfor Coal MineAbstract.According to statistic data of China in recent years, gas explosion accounted for above 70% in all coal mine accidents. Frequent gas explosion accidents have caused great losses of lives and property. Therefore gas detection and monitoring system is needed to serve as a safety device in coal production. In this paper, an intelligent gas detecting system is designed. This detection instrument adopts SCM AT89S52 as its control hardcore and uses catalytic bustion type gas sensor element MC112 as the sensor for gas (CH4) detecting.The main functions of this system are as follows: monitoring the realtime concentration of CH4 and displaying the concentration value。 emitting sound and light alarm signals if the CH4 concentration value is beyond the alarm value inputted by keyboard panel。 using serial munication port to transmit data to the host puter above ground. The software debugging and hardware simulating of the system above are also implemented at the same time.Keywords: Data collection, Sensor, Coal mine, Serial munication, SCM.1. IntroductionAs the most important source of energy in China, Coal consumption is about 70% of all the energy consumption [1,2]. However, coal mine accident happened frequently in China, lots of people suffered from these disasters. Among all the accident, gas leakage lead to gas explosion is the main reason of these accidents [3,4]. So, it’s significantly important to develop gas monitoring safety system in coal production enterprises. In this paper, a gas detection and monitoring system is presented, its main functions including Realtime monitoring gas concentration, transmitting dynamic safety operation parameters underground coal mine, automatic warning about danger before accident happens and providing useful information on rescuing and evacuating people or equipment to decision makers. Design of Gas Detecting SystemGas detecting system should meet some specific needs: it can monitoring bustible gas concentration underground coal mine, warning against over standard gas concentration and transmitting real time data to host puter above ground [5, 6]. The gas detecting system in this paper adopts singlechip microputer as control puter。 the overall schematic diagram of system is shown in Figure 1. The reason for selecting singlechip microputer as a control core is that it possesses advantages of small size, high reliability, low price which made it very suitable to be used in industries of intelligent instrument and real time control field [7].The operating interface of system is shown in Figure 2. Number at upper right corner shows the default or userdefined gas concentration value, number at upper left corner shows detected gas concentration value. One alarm lamp is equipped. All functions are controlled by keys arranged on the control panel, including POWER key, RESET key, DATA COLLECTION key. Other keys including ten number keys, ADJUST VALUE key and ENTER key are used to change threshold values. Basic operating procedures are as follows:Firstly press POWER key, the system initialized. Press DATA COLLECTION key, LED at upper right corner displays the thre shold value 。 User can customized threshold value by press ADJUST VALUE key and ten number keys, then press ENTER to confirm the change. System starts to detect gas concentration and display these parameters on upper left LED area, at meantime transmit realtime data by RS485 to host puter above ground.3Hardware System Design of Gas Detection System。The Hardware architecture of system mainly including main control unit, sensors and signal amplifier circuit, A/D converter module, soundlight alarming circuit, keyboard and display module, serialmunication module. Main Control UnitFeatured by high integration level, small size and low prices, Single chip microputer has been widely used in a broad range of industrial applications including process controlling, data collection, electromechanical integration, intelligent instrument, household appliances and network technology, and significantly improved the degree of technology and automation. Two factors are taken into account here in chip selecting, first one is antiinterference ability, the poor working conditions and plex operating situations in mine tunnel increase the interferences in SCM application systems, so the SCM must have high resistance to outside interference。 second one is the performanceprice ratio of the SCM. Considering the aforementioned factors, we adopted the AT89S52 developed by ATMEL as main control unit, and the final scheme of main control circuit consists of AT89S52, timer and reset circuit [8,9]. Sensors and Signal Amplifying Circuit Sensor Selection A crucial issue in gas detecting system design is how to select gas sensors. Common gas sensors are metal oxide semiconductor such as tin oxide