The STWD100 watchdog timer circuits are self-contained devices which prevent systemfailures that are caused by certain types of hardware errors (non-responding peripherals,bus contention, etc.) or software errors (bad code jump, code stuck in loop, etc.).The STWD100 watchdog timer has an input, WDI, and an output, WDO (see Figure 2). Theinput is used to clear the internal watchdog timer periodically within the specified timeoutperiod, twd (see Section 3: Watchdog timing). While the system is operating correctly, itperiodically toggles the watchdog input, WDI. If the system fails, the watchdog timer is notreset, a system alert is generated and the watchdog output, WDO, is asserted (seeSection 3: Watchdog timing).The STWD100 circuit also has an enable pin, EN (see Figure 2), which can enable ordisable the watchdog functionality. The EN pin is connected to the internal pull-downresistor. The device is enabled if the EN pin is left floating.
基于多點網(wǎng)絡(luò)的水廠自動監(jiān)控系統(tǒng)設(shè)計Design of MPI Based Automatic Monitoring and Control System in Water Works劉 美 俊(湖南工程學(xué)院,湘潭411101)摘要針對水廠工作水泵多、現(xiàn)場離控制站距離遠的特點,提出了一種基于MPI多點網(wǎng)絡(luò)的自動監(jiān)控系統(tǒng)的設(shè)計方法,分析了系統(tǒng)的工作原理,介紹了系統(tǒng)中數(shù)據(jù)的采集與處理、主站與從站的通信原理以及系統(tǒng)軟件的設(shè)計。由于這種系統(tǒng)的主、從站PLC之間采用MPI網(wǎng)絡(luò)通信,具有運行可靠、性能價格比高的特點,所以適用于中小規(guī)模水廠的分布式監(jiān)控場合。關(guān)鍵詞多點網(wǎng)絡(luò)主站從站監(jiān)控系統(tǒng)Abstract Ina ccordancew ithth efe atuersof w aterw orks,i. e. ,manyp umpsin o perationa ndth ep umps, farfor mt hec ontrolst ation,th em ethodo fdesigninga na utomati(〕monitoringa ndc ontorlsy stemb asedo nM PIis p resented.Th eo perationalpr incipleo fth esy stemi san alyzed,th ed atac olection,data processing; communication between master station and slave station as wel as design and system software are discussed. Because MPI network communicationis used among master station, slave stations and PLC, the system is reliable and high cost-efective. It is, suitable for smal and mediumsized water works for distrbuted monitoring and control.Keywords MPI Masterst ation Slaves tation Monitoringa ndc ontorlsy stem
自來 水 廠 的自動控制系統(tǒng)一般分為兩大部分,一對組態(tài)硬件要求較高,投資較大。相對而言,MPI網(wǎng)是水源地深水泵的工作控制,一是水廠區(qū)變頻恒壓供絡(luò)速度可達187.5 M bps,通過一級中繼器傳輸距離可水控制,兩部分的實際距離通常都比較遠。某廠水源達Ikm 。根據(jù)水廠的具體情況,確定以MPI方式組地有3臺深井泵給水廠區(qū)的蓄水池供水。水廠區(qū)的成網(wǎng)絡(luò),主站PLC為S7-300系列的CPU3121FM,從任務(wù)是對水池的水進行消毒處理后,通過加壓泵向管站為S7-200系列的CPU222。這樣既滿足了系統(tǒng)要路恒壓供水。選用Siemens公司的S7系列可編程控求,又相對于Profibus網(wǎng)絡(luò)節(jié)省了三分之一的成本,制器(PLC)和上位機組成實時數(shù)據(jù)采集和監(jiān)控系統(tǒng), 這種分布式監(jiān)控系統(tǒng)具有較高的性能價格比。系統(tǒng)對深水泵進行遠程控制,對供水泵采用變頻器進行恒中PLC的物理層采用RS - 485接口,網(wǎng)絡(luò)延伸選用壓控制以保證整個水廠的電機設(shè)備安全、可靠地運帶防雷保護的中繼器,使系統(tǒng)的安全運行得到了保行。證。MPI網(wǎng)絡(luò)的拓撲結(jié)構(gòu)如圖1所示。1 多點網(wǎng)絡(luò)(NWI)監(jiān)控系統(tǒng)的組成Sie me ns 公司S7系列PLC通常有MP」多點網(wǎng)絡(luò)與Profibus現(xiàn)場總線網(wǎng)絡(luò)兩種組網(wǎng)方式。Profibus現(xiàn)場總線的應(yīng)用目前較為普遍,通用性較好,它由Profibus一DP, Profibus一FMS, Profibus一PA組成。Profibus - DP型用于分散外設(shè)間的數(shù)據(jù)傳輸,傳輸速率為9.6kbps一12Mbps,主要用于現(xiàn)場控制器與分散1/0之間的通信,可滿足交直流調(diào)速系統(tǒng)快速響應(yīng)的時間要求,特別適合于加工自動化領(lǐng)域的應(yīng)用;Profibus - FMS主要解決車間級通信問題,完成中等傳輸速度的循環(huán)或非循環(huán)數(shù)據(jù)交換任務(wù),適用于紡織、樓宇自動化、可編程控制器、低壓開關(guān)等;Profibus - PA型采用了OSI模型的物理層和數(shù)據(jù)鏈路層,適用于過程自動化的總線類型。
基于單片機的汽車多功能報警系統(tǒng)設(shè)計The Design of Automobile Multi-function AlarmingBased on Single Chip Computer劉法治趙明富寧睡達(河 南 科 技 學(xué) 院 ,新 鄉(xiāng) 453 00 3)摘要介紹了一種基于單片機控制的汽車多功能報警系統(tǒng),它能對汽車的潤滑系統(tǒng)油壓、制動系統(tǒng)氣壓、冷卻系統(tǒng)溫度、輪胎欠壓及防盜進行自動檢測,并在發(fā)現(xiàn)異常情況時,發(fā)出聲光報警。闡述了該報警系統(tǒng)的硬件組成及軟件設(shè)計方法。關(guān)鍵詞單片機傳感器數(shù)模轉(zhuǎn)換報警Abstract Am ulti-fimctiona utomobilea larnungs ystemb asedo ns inglec hipc omputerco ntorlis in torducedin th isp aper.Th eo ilpr essuero flu bricatesystem, air pressure of braking system, temperature of cooling system, under pressure of tyre and guard against theft, detected automaticaly場thesystem. Audio and visual alarms wil be provided under abnormal conditions廠The hardware composition and software design of the system, described.Keywords Singlec hipc omputer Sensor Digital-t-oanaloguec onversion Alarmin
汽車多功能報苦器硬件系統(tǒng)設(shè)計根據(jù) 系 統(tǒng) 實際需要和產(chǎn)品性價比,選用ATMEL公司新生產(chǎn)的采用CMOs工藝的低功耗、高性能8位單片機AT89S52作為系統(tǒng)的控制器。AT89S52的片內(nèi)有8k Bytes LSP Flash閃爍存儲器,可進行100(〕次寫、擦除操作;256Bytes內(nèi)部數(shù)據(jù)存儲器(RAM);3 2 根可編程輸N輸出線;2個可編程全雙工串行通道;看門狗(WTD)電路等。系統(tǒng)由傳感器、單片機、模數(shù)轉(zhuǎn)換器、無線信號發(fā)射電路、指示燈驅(qū)動電路、聲光報警驅(qū)動電KD一9563,發(fā)出三聲二閃光。并觸發(fā)一個高電平,驅(qū)動無線信號發(fā)射電路。
單片機系統(tǒng)“PC”失控的軟件措施Software Measure of GettingO uto fC ontrolfo r“PC"in S ingleC hipC omputerS ystem謐 加 春 王 曉 基 雷 小 華(江 西 理 工 大 學(xué)機 電 工 程 學(xué) 院 ,贛 州 34 10 00)摘要單片機系統(tǒng)在實際工業(yè)現(xiàn)場中可能遇到各種干擾和自身的隨機性故障。現(xiàn)場惡劣的環(huán)境有可能使計算機系統(tǒng)發(fā)生異常,計算機程序指針“PC”失控就是常見的故障之一,如果發(fā)生“PC”失控,將導(dǎo)致CPI工作混亂,釀成嚴重的事故。研究了“PC”失控的原因,并指出軟件抗干擾的幾種方法,有效保證單片機系統(tǒng)的正常工作。關(guān)鍵詞單片機“PC”失控抗干擾Abstract Inp racticalin dustrialfi elds,th ereis v ariousin terferencea fectingo perationo fsi nglec hipc omputersy stemsa ndt hec omputersy stems。fac噸random faults飾themselves. It is very common that the severe environment makes the computer systems abnormal. The program counter "PC"gettingo utof co ntorlis on eo fth ec ommonfa ults.If th isoc curs,C PUw ouldb eru nningo utof or deran din torducesse riousan cient.T hec ausesof " PC"geting out of control, studied in this paper and some countermeasures of anti-interference師software are given to ensure single chip computer systemworking properly.Keywords Single。飾computer Porgramc ounter"P C" Anti-interfeernc
在設(shè) 計 和 開發(fā)單片機系統(tǒng)時,一般難以周全地預(yù)計單片機系統(tǒng)在實際工業(yè)現(xiàn)場中可能遇到的各種干擾和自身的隨機性故障。因此,除了采取防止和抑制干擾的各項措施外,還應(yīng)該借助于軟件措施克服某些干擾,系統(tǒng)還應(yīng)具備迅速自行恢復(fù)的能力。本文介紹的應(yīng)對單片機系統(tǒng)PC失控的軟件措施,設(shè)計靈活,節(jié)省硬件資源,能保證測控系統(tǒng)長期可靠地運行。MC S- 5 1單片機以其優(yōu)良的性能價格比大量應(yīng)用于工業(yè)現(xiàn)場測試和控制領(lǐng)域。但是,現(xiàn)場惡劣的環(huán)境有可能使計算機系統(tǒng)發(fā)生異常,計算機程序指針PC失控就是常見的故障之一,一旦發(fā)生PC“走飛”,計算機系統(tǒng)就會出現(xiàn)工作混亂,釀成嚴重的事故。為 了 在 CP 失控時盡量減少由此帶來的不利影響,并盡快使系統(tǒng)恢復(fù)正常,需要采取一定的軟件措施和硬件措施。常見的硬件措施有“看門狗”電路。軟件措施設(shè)置的前提條件是:①在干擾作用下,微機系統(tǒng)硬件部分不會受到任何損壞,或者損壞部分設(shè)置有監(jiān)測狀態(tài)可供查詢;②程序區(qū)不會受到干擾侵害。單片機系統(tǒng)的程序和表格以及重要的參數(shù)均設(shè)置在ROM區(qū),不會因干擾的侵人而改變;③ RAM區(qū)中的重要數(shù)據(jù)不會被破壞,或者雖然被破壞,但是可以重新建立。
基于ADSP-BF561的數(shù)字攝像系統(tǒng)設(shè)計Design of Digital Video Camera System Based on Digital Signal ProcessorADSP-BF561(浙江大學(xué) 信息與通信工程研究所,浙江 杭州 310027) 馬海杰, 劉云海摘要:介紹了基于ADI雙核的數(shù)字信號處理芯片ADSP-BF561 的數(shù)字攝像系統(tǒng)實現(xiàn)方案。系統(tǒng)包括硬件和軟件兩部分,硬件主要有ADSP-BF561及其外圍電路、音視頻模數(shù)/數(shù)模轉(zhuǎn)換、CF卡/微硬盤接口等部分。軟件主要有操作系統(tǒng)及音視頻編解碼算法等部分。關(guān)鍵詞:ADSP-BF561 ;數(shù)字攝像機;微硬盤;MPEG-4;A/D;D/A中圖分類號:TN948.41文獻標識碼:AAbstract: An implementation of digital video camera system based on ADI dual core digital signal processor ADSP-BF561 is introduced. The system can be divided into two parts——hardware and software design. The hardware design includes ADSP-BF561 and perpheral apparatus, A/D,D/A, CF card or Microdrive and so on. The software includes operating system , audio and video coding algorithm.Key words: ADSP-BF561; digital video camera; microdrive; MPEG-4;A/D;D/A
設(shè)計一種應(yīng)用于某全地形ATV車載武器裝置中的中控系統(tǒng),該系統(tǒng)設(shè)計是以TMS320F2812型DSP為核心,采用模塊化設(shè)計思想,對其硬件部分進行系統(tǒng)設(shè)計,能夠完成對武器裝置高低、回轉(zhuǎn)方向的運動控制,實現(xiàn)靜止或行進狀態(tài)中對目標物的測距,自動瞄準以及按既定發(fā)射模式發(fā)射彈丸和各項安全性能檢測等功能。通過編制相應(yīng)的軟件,對其進行系統(tǒng)調(diào)試,驗證了該設(shè)計運行穩(wěn)定。
Abstract:
A central control system applied to an ATV vehicle weapons is designed. The system design is based on TMS320F2812 DSP as the core, uses modular design for its hardware parts. The central control system can complete the motion control of the level of weapons and equipment, rotation direction, to achieve a state of static or moving objects on the target ranging, auto-targeting and according to the established target and the projectile and the launch of the security performance testing and other functions. Through the development of appropriate software and to carry out system testing to verify the stability of this design and operation.
針對運行中火車測速運用多普勒效應(yīng)采用DSP 設(shè)計雷達測速系統(tǒng)并闡述了其基本設(shè)計思想與工作原理給出系統(tǒng)硬件軟件設(shè)計結(jié)構(gòu)和原理圖改善了原有光電測速精度提高了系統(tǒng)工作穩(wěn)定性和可靠性經(jīng)實驗證明DSP 采集板工作穩(wěn)定測速效果好關(guān)鍵詞DSP; 雷達測速; 多普勒效應(yīng)
On Board DSP-Based Radar Speed Measurement System TANG Wei, SUN Zhi-fang, CHEN Quan (Dept.of computer Science,Yangtze University,Jingzhou 434023,China)Abstract: This paper presents a DSP-based train speed measurement by using Doppler radar. The structure of the system is introduced.The hardware and software are also discussed.Key words: DSP; rader speed measurement; doppler principle