【正文】 ation of building. With the development of the fieldbus technology, its advantage has became more and more notable in the field of puter39。舉例來說，溫度首先由鉑電阻采集。并根據(jù)該方案完成了下位機(jī) (PLC 控制程序 )的編制和上位機(jī) (監(jiān)控軟件和人機(jī)界面的組態(tài) )的組態(tài)。 現(xiàn)場總線技術(shù)的不斷發(fā)展，其在計算機(jī)集散控制領(lǐng)域的優(yōu)勢已越來越明顯。 PROFIBUS 是國際上應(yīng)用十分廣泛的工業(yè)過程現(xiàn)場總線，主要應(yīng)用于加工自動化、過程自動化、樓宇自動化等領(lǐng) 域。文章對閘門啟閉機(jī)及其控制系統(tǒng)的發(fā)展?fàn)顩r和傳統(tǒng)液壓啟閉機(jī)控制系統(tǒng)的局限性進(jìn)行了詳細(xì)分析，并結(jié)合當(dāng)前控制技術(shù)，特別是 Profibus 現(xiàn)場總線控 制技術(shù)的特點，針對所研究的水電站的實際情況提出了“基于 Profibus現(xiàn)場總線控制和以太網(wǎng)技術(shù)的閘門監(jiān)控系統(tǒng)”的技術(shù)方案。 1）模擬數(shù)據(jù)的采集和轉(zhuǎn)換 模擬輸入和輸出，例如需要在線測量的壓力和溫度。 information work under different situations. With the rapid development of information technology, a deep change has taken placed in the industry process control field. The simple control theory used in this field for years can39。 today it has developed into a powerful control system with the central of processor and has many functions such as all kinds of calculations control and work. With its excellent stability and powerful functions, PLC is now widely used in manufacture industry, electric power field, traffic field and etc. The PLC program uses a cyclic scan in the main program loop such that periodic checks are made to the input variables. The program loop starts by scanning the inputs to the system and storing their states in fixed memory locations (input image memory). The ladder program is then executed rungbyrung. Scanning the program and solving the logic of the various ladder rungs determine the output states. The updated output states are stored in fixed memory locations (output image memory). The output values held in memory are then used to set and reset the physical outputs of the PLC simultaneously at the end of the program scan. As we know, logic control is a remarkable property of PLC, and it can be applied to efficiently handle analog data. 1) Analog data acquisition and transformation Analog inputs and outputs such as pressure and temperature need to be measured online. For instance, temperature is first acquired by the Platinum resistances. A signal transformation module then converts the measured resistance value into the voltage range of 15V. The output of this transformation module is finally collected and transmitted back to the above PLC. 2) PLC control algorithms The analog variables could be any controlled variable, ., temperature or pressure in our winding system. As a matter of fact, there exist two control modes, auto and manual. In the manual mod