基于Profibus实现netLINK网关与PLC的通讯

对上位机与底层PLC运动控制模块的研究发现,上位机具有强大的计算能力和稳定的数据存储,PLC运动控制模块是设备运行的核心。将两者运用netLINK通讯模块进行连接,在数据计算和存储便捷的同时,将会使运动系统更加稳定。     

基于PowerPC对FPGA上电自动加载的设计与实现

为了满足FPGA在每次上电后可以实现自动加载的要求,采用由PowerPC、Xilinx A7系列FPGA芯片、Xilinx K7系列FPGA芯片和Flash芯片组成的系统,上位机通过串口给PowerPC发送指令,PowerPC解析指令后读取上位机中的配置加载文件,文件数据通过Local bus总线传给A7系列FPGA芯片,把数据写入Flash中存储。上电后,在A7的控制下把存储在Flash中的配置文件自动加载到K7中。此系统在处理大数据量、运行高速数据接口和协议等复杂应用的同时,通过上位机方便快捷地更新配置加载文件,实现对Xilinx K7系列FPGA芯片的上电自动加载功能。在满足设计要求的基础上不需要增加专门的硬件电路实现加载功能,节约了成本,减少了电路板面积和器件的使用。     

基于文件管理的高速存储系统的设计与实现

随着存储设备的高速发展,智能化、高速化、小型化成为不断突破的技术核心。通过增加文件管理模式,设计了高速存储系统。为提高数据传输带宽,使用以太网接口,同时接收多路数据。为保证存储模块重新上电之后可以继续存储通过实时更新存储的操作地址。数据读取时,使用高速串口,提高读出速度。测试结果表明,Flash阵列的数据写入速度为75 Mbyte/s。上位机读取速度为384 Mbit/s,将存储的文件以data文件读出。可见系统准确性高、实用性强,且设备趋向小型化发展。     

基于STM32F103的USB主机接口设计

嵌入式USB主机系统在数据存储和交换领域具有很好的应用前景.为了存储和处理嵌入式系统中的大量数据,一种方法是让嵌入式系统具有USB设备接口,以通讯的方式向上位机不断转储RAM中的数据;另一种方法就是让嵌入式系统具有USB主机接口,使嵌入式系统可以直接读写U盘或SD卡之类的移动存储设备,再通过移动存储设备将数据转储到上位机中,不需要嵌入式系统与上位机之间有直接的通讯连接.使用USB控制芯片CH376设计了一个基于STM32F103的USB主机接口,并应用于嵌入式系统中.     

基于嵌入式MCU数据Flash的数据存储及管理方法研究与实现

本文设计了一种利用MCU内部数据Flash存储非易失性数据的方法,它将数据Flash的若干扇区划分为多个数据分区,不同数据分区存储数据在不同历史时间的拷贝,最新数据分区存储最新的数据拷贝;在数据读操作进行时,计算最新数据拷贝的Flash存储位置,直接读取该地址;在数据写操作进行时,判断数据写入位置是否已经被擦除,如果写入位置未擦除,将数据写入下一个分区,同时将当前分区中的其他数据复制到下一个分区;如果写入位置已经擦除,直接将数据写入当前分区中。该方法实现了类似EEPROM的数据读写方式,操作方便,应用接口简单,而且可以尽量避免扇区擦除操作,提高存储效率,同时提高MCU内部数据Flash的使用寿命。本文网络版地址：http：//www.eepw.com.cn/article/170167.htm     

计算机链接通讯在三菱PLC与变频器中的应用

本文主要介绍了计算机（上位机三FX2N系列PLC）通过计算机链接方式主动发送指令与可编程序控制器（下位机三菱FX2N系列PLC]和下位机三菱A700系列变频器之间实现通讯的方法。详细讲解实现计算机链接通讯所需的硬件条件,各设备参数的设置,通讯程序等。使用计算机链接通讯可以实现一台上位机三FX2N系列PLC时与16台下位机三菱FX2N系列PLC和32台下位机三菱A700系列变频器之间的通讯。     

一种新的程序在线升级的实现

介绍一种新的程序在线升级方法,以及程序在线升级方法[1]在嵌入式系统中的应用和实现.设计将从系统原理和实现介绍该程序在线升级方法[2].设计的核心处理器采用飞思卡尔MC9S12xDT512控制器,利用串口作为通讯方式,自定义通讯协议.上位机将升级文件传送给下位机,下位机将数据解析后存储在内部Flash中.解析成功后下位...     

基于VC的PLC数据采集管理系统

介绍基于VC++的工控机与多台OMRON CJIG-H PLC组成的数据采集管理系统的实现.用RS 485连接上位机与现场10台PLC,在上位机中建立数据库和安装数据采集管理软件,通过总线将各台PLC的数据采集到上位机的数据库中统一管理.采用VC设计上位机界面、通信程序和作为数据库管理的前台开发语言;后台数据库软件采用SQL Server2000;上位机与PLC之间采用OMRON的Host Link通信协议.将SQL Server 2000与PLC结合起来,弥补了PLC存储、管理大量数据能力不足的缺陷.通过此系统,用户可方便地在上位机中存储、查看和打印下位机(PLC)中的信息,监视PLC的工作状态.现场的运行结果显示该系统使用方便,性能可靠.     

用梯形图语言编写通讯校验程序

PLC与上位机通讯存在错误码问题，用梯形图语言计算CRC校验码，将数据和通讯校验码一并传送上位机，上位机计算校验码CRC后，判别接收数据正误。决定放弃或使用数据。解决了通讯存在的错误码问题。     

西门子PLC与计算机间的通讯程序设计

介绍了西门子（Siemens）公司生产的S7－200型PLC与计算机之间的通讯网络构成及主要通讯指令，说明了利用PLC进行通信的实质和设计步骤，给出了PLC与计算机通讯时上位机和下位机的相应程序。     

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.     

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.     

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.     

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.     

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.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

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.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.