【正文】 濰坊學院?？飘厴I(yè)（論文）I目錄第一章 概 述 ........................................................................................2 .....................................................3 .............................................................5第二章 硬 件 電 路 設 計 .........................................................................7 ..............................................8 ...................................................9 ........................................................10 ........................................................15 數(shù)模轉換環(huán)節(jié) .......................................................15 V/I變換電路設計 ....................................................17 ................................................18 ............................................................19 RS－485 協(xié)議簡介及 MAX485芯片介紹 ...............................19 提高 RS485網(wǎng)絡可靠性的措施: ....................................20(看門狗)電路設計： ..........................................20 X5045引腳介紹 ..................................................21： ......................................................21第三章 軟件系統(tǒng) ......................................................................................24 ....................................................24 ........................................................35 ADC模塊 ...........................................................35 濾波及標度變換環(huán)節(jié) .................................................36 DAC模塊 ............................................................38 通訊模塊 ...........................................................39 RS485串行通信協(xié)議 .............................................39濰坊學院專科畢業(yè)（論文）II ......................................................40 協(xié)議的格式 ..............................................40第四章 實際電路圖 ...................................................................................45第五章 總 結 ...........................................................................................48第六章 參 考 文 獻 ..................................................................................48致謝 .......................................................................................................36濰坊學院?？飘厴I(yè)（論文）III智能變送器的設計摘要近年來，隨著微電子技術的發(fā)展，智能 變送器對工業(yè)自動化越來越重要。智能式 變送器比電容式或擴散硅式傳統(tǒng)變送器的價格高 50％左右， 但智能式變送器的性能、功能很優(yōu)越，因此性能價格比 較高。智能 變送器的應用 領域是非常廣泛的，使用智能 變送器無疑會給社會和用戶帶來更多的效益。變送器是工業(yè)過程重要的基礎自動化設備之一。主要完成物理信號的測量和變換處理。隨著生產的發(fā)展，生產規(guī)模的擴大，高參數(shù)、大容量設備不斷增加，相應的過 程工藝自動化管理系統(tǒng)日趨復雜，變送器用量不斷增多， 對性能的要求不斷提高本設計總體上從硬件電路設計和軟件設計上進行了研究探討。硬件電路設計主要包括主機電路、過程輸入/輸 出通道、人機接口 電路和通信接口電路等功能模板。內容涉及器件的選擇和電路設計連接，通過分析與比較選定合適的芯片，達到既能滿足系統(tǒng)的性能需求，又可充分發(fā)揮芯片本身的性能，避免不足和浪費。 設計電路時，盡可能采用經(jīng)典的線路，力求標準化；電路中的相關器件性能須匹配；為確保儀器能長期可靠運行，還須采取相應的抗干擾措施，包括去耦濾波、合理的走 線 、通道的隔離等。軟件設計部分主要是設計軟件系統(tǒng)的模塊層次結構、控制流程以及數(shù)據(jù)庫的結構等。這個階段可以分為兩個部分；總體設計和詳細設計?？傮w設計完成軟件系統(tǒng)的模塊劃分，設計層次結構、確立模塊間的凋用及完成全局數(shù)據(jù)庫的設計等工作；詳細設計完成每個模塊的內部實現(xiàn)算法、控制流程以及周部數(shù)據(jù)結構的設計。 關鍵詞：智能變送器 ；模塊 ；電路設計；通信濰坊學院專科畢業(yè)（論文）IVIntelligent pressure transmitter designABSTRACT In recent years, with the development of the microelectronics technology of industrial automation, intelligent pressure transmitter bees more and more important. Intelligent type transmitter than capacitive or proliferation silicon type of traditional transmitter around 50% of high price, but intelligent type of transmitters performance, function very superior, therefore performance price is quite high. Intelligent pressure transmitter is very wide applications, using intelligent pressure transmitter to the society and users will no doubt bring more benefit. this design overall Transmitter is industrial process important one of basic automation equipment. Main physical signal measurement and finish transformation to deal with. With the development of production, the production scale expands, high parameter, highcapacity equipment increases unceasingly, the corresponding process automation management system is plicated, transmitter to increase, dosage of performance requirements enhances unceasingly om hardware circuit design and software design were also discussed. Hardware circuit design includes host circuit, process input/output channel, manmachine interface circuit and munication interface circuit and other function templates. Content involves device of choice and circuit design connection, by analyzing and paring the designation appropriate chip, 濰坊學院?？飘厴I(yè)（論文）Vachieve both can satisfy the system performance requirements, and can give full play to the performance of the chips themselves, avoid deficiencies and waste. Circuit design, use as far as possible classic lines, and strive to standardization。 The relative device performance circuit must be matching。 In order to ensure the longterm reliable operation, instrument can still must adopt corresponding antiinterference measures, including decoupling filtering, reasonable go line, channel segregation, etc. The software design part mainly design software system module structure, control process and database structure, etc. This phase can be divided into two parts。 The overall design and detailed design. The overall design pleted software system module partition, design structure, establishing the between modules fitted with and pleted the design work global database。 The detailed design of the pletion of each module internal implementation algorithms, control flow and weeks of data structure design department. KEYWORDS: Intelligent transmitter。 module。 circuit design。 munication 濰坊學院?？飘厴I(yè)（論文）1前言變送器是工業(yè)過程重要的基礎自動化設備之一。主要完成物理信號的測量和變換處理。隨著生產的發(fā)展，生產規(guī)模的擴大，高參數(shù)、大容量設備不斷增加，相應的過程工藝自動化管理系統(tǒng)日趨復雜，變送器用量不斷增多，對性能的要求不斷提高。近年來隨著微電子技術的飛速發(fā)展，尤其是近年來由于低功耗、多功能單片微處理器、高精度∑△、A／D 與 D／A 變換器件的面世，為研制通用型高精度智能變送器創(chuàng)造了條件。諸如溫度、濕度、流量、位移等物理量的測量與控制，如何提高系統(tǒng)的可靠性與精度，減少外部連接線，量程浮動、輸出信號可遠傳和隨量程線性轉移，以及一機多用（以同一檢測模板用于不同物理量的檢測場合） ，并滿足多種線性與非線性輸入信號的精度要求等課題，已越來越為廣大科技人員所關注。世界上一些主要的儀表制造廠也相繼研制成功了帶微處理機構各種智能變送器，開創(chuàng)了“智能式變送器”的新階段。本設計總體上可也分為兩部分，硬件電路設計和軟件設計硬件電路設計主要