PLC＆DCS

PLC可编程序控制器：PLC英文全称Programmeble Logic Controller，中文全称为可编程逻辑控制器，定义是：一种数字运算操作的电子系统，专为在工业环境应用而设计的。它采用一类可编程的存储器，用于其内部存储程序，执行逻辑运算。顺序控制，定时，计数与算术操作等面向用户的指令，并通过数字或模拟式输入／输出控制各种类型的机械或生产过程。     

什么是PLC

PLC的定义有许多种。国际电工委员会（IEO）对PLC的定义是：可编程控制器是一种数字运算操作的电子系统．专为在工业环境下应用而设计。它采用可编程序的存贮器．用来在其内部存贮执行逻辑运算、顺序控制、定时、计数和算术运算等操作的指令．并通过数字的、模拟的输入和输出，控制各种类型的机械或生产过程。可编程序控制器及其有关设备，都应按易于与工业控制系统形成一个整体．     

浅谈可编程控制器在机组自动化操作中的应用

文章简述了可编程控制器的定义和结构,举例说明了可编程控制器在机组自动化操作中的应用,并对可编程控制器构成机组自动化操作的特点作了论述。     

基于可编程控制器的稳压器压力水位控制研究

本文研究了可编程控制器构建稳压器压力水位控制系统。通过对可编程控制器的软件控制技术、配置的灵活性、模块化结构以及功能模块的运用,能够保证稳压器压力水位控制系统自身的功能的实现。通过分析相关的实验结果,我们发现在控制水位以及稳压器压力的时候利用可编程控制器是完全可行的。     

如何利用PLC来判断机电设备的故障

随着信息化自动的快速发展, PLC可编程逻辑控制器在我公司使用越来越多,它采用可编程的存储器,用于其内部存储程序,执行逻辑运算、顺序控制、定时、计数与算术操作等面向用户的指令,并通过数字或模拟输入/输出控制各种类型的机械或生产过程.它具有丰富的输入/输出接口,并且具有较强的驱动能力.目前我公司部分设备采用PLC集中自动控制,应用PLC可使机电设备的生产效率人幅提高,同时也可为机电设备的故障诊断带来极大的方便,PLC应用的深度和广度巳成为一个国家工业先进水平的重要标志.     

探析可编程控制器在电气控制中的应用

近年来,可编程控制器在多个领域得到了广泛应用,如机械工程领域、自动化控制领域以及工业自动化控制领域等.这也在一定程度上说明可编控制器应用具有较高的价值,它以稳定性高、控制水平高以及抗感染能力强等特点在社会生产中占据越来越重要的位置.本文将对可编程控制器在电气控制中的具体应用进行分析,以供参考.     

可编程控制器在电梯数据监控系统中的应用

可编程控制器的出现符合了工业高自动化的需求,其具有高超的操作性能、自动性能与低廉的成本以及极强的适应能力。在现代化的城市中不乏高楼建筑,而在这些高层的建筑中,电梯已成为必备品。现代化的电梯设计大多会引用相应的可编程控制系统来监控其运行,可编程控制器对于电梯来说具有提高灵活性、可靠性、使用寿命等方面作用。特别是将PLC与变频调速技术结合引用,使得我们对电梯的控制达到了理想的效果。本文将对电梯中的可编程控制器的应用做详细的阐释介绍。     

Omron公司的可编程终端

Omron公司推出NT600S大型可编程终端,其用处是同可编程控制器组合在一起作为生产装配线上的操作显示板。其显示区域为192×120mm,并采用液晶混合物支持STN型LCD(液晶显示器),这种液晶显示器可以在户外和光线强的地方使用。     

学好可编程控制器,面向广阔应用空间

可编程控制器应用技术是职业院校机电专业必修的课程,也是工农业生产一线技术人员必须掌握的专业技术。可编程控制器应用技术简单易学,在工农业生产中应用又十分广泛,掌握这一技术对促进工农业生产现代化,提高生产力,进而提高综合国力都具有十分重要意义。本文通过对可编程控制器的产生,结构特点,学习方法,应用范围进行简要分析,从而坚定学好可编程控制器的信心,进而在实践中用好可编程控制器。     

Plc设备应用与维护

PLC作为高性能微机化自控设备,目前已得到十分广泛的应用,随着信息化自动的迅速发展,PLC可编程逻辑控制器在贵公司使用越来越多,它采用可编程的存储器,控制技术、计算机技术、通信技术和传感器技术的发展,PLC的功能越来越强,PLC的应用越来越广,控制对象越来趣复杂,控制要求也越来越高,用于其内部存储程序,执行逻辑运算、顺序控制、定时、计数与算术操作等面向用户的指令,并通过数字或模拟输入／输出控制各种类型的机械或生产过程。它具有丰富的输入／输出接口,并且具有较强的驱动能力。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.