CAN-Ethernet总线通信协议转换器的研究

随着先进制造技术的数字化、网络化、智能化,现场总线技术和嵌入式技术相结合必将产生深远的影响。文中介绍基于ARM的CAN-Ethernet总线通讯协议转换器的总体设计和实现Modbus TCP的设计架构,Modbus/TCPIP服务器端的设计。采用CAN总线协议与Modbus/TCPIP协议进行转换的方式来实现便捷低成本的协议转换器,着重介绍了设备的固件程序,驱动程序,应用程序的设计和具体实现。     

工业嵌入式多协议转换器的研究与应用

文中介绍了嵌入式多协议转换器的研究,在介绍了Modbus和Profibus-DP两种现场总线协议模型的基础上,提出实现应用的软、硬件设计方法,并结合隧道监控系统工程应用,探讨了自定义协议转换Modbus协议,以及Modbus转换Profibus-DP协议。     

电动钻机柴油发电机组控制系统通信单元设计

在开发电动钻机柴油发电机组数字式控制器过程中,需要实现其与电动钻机控制系统之间的通信功能.基于现场总线器件,设计一种能够实现Profibus-DP与CAN总线协议转换功能的通信单元,该单元由Profibus-DP从站接口电路和CAN节点电路组成,应用双口RAM器件实现两者之间的数据交换.该方案完善了电动钻机控制系统的总线控制方式,有利于提高产品的数字化程度.     

电动钻机柴油发电机组控制系统通信单元设计

在开发电动钻机柴油发电机组数字式控制器过程中,需要实现其与电动钻机控制系统之间的通信功能。基于现场总线器件,设计一种能够实现Profibus—DP与CAN总线协议转换功能的通信单元,该单元由Profibus—DP从站接口电路和CAN节点电路组成,应用双口RAM器件实现两者之间的数据交换。该方案完善了电动钻机控制系统的总线控制方式,有利于提高产品的数字化程度。     

嵌入式LonWorks/Ethernet/Modbus网关的研究与设计

在工业通信中因为历史、技术、设备厂家等原因,存在LonWorks/Ethernet/Modbus三种现场总线并存而相互间无法兼容的问题。本文目的是研究与设计一种嵌入式协议转换网关,把这三种总线有机的兼容在一起。     

STEC2000控制器在LonWorks总线中应用

随着总线技术以及通信技术的日趋成熟,远程监控已经成为了现实。接口的多样性已经成为继稳定性以后评价控制器的一项重要标准。Modbus以及LonWorks是当前比较流行的两种总线技术,由于协议是公开的,所以可以通过添加网关来实现两种总线间的转换,从而实现多种控制器之间数据的快速交换,达到控制的目的。结合燃气锅炉监控工程,本文阐述了使用STEC2000控制器实现两种通信协议的转换过程。     

助航灯光监控系统的CAN-Modbus智能网桥设计

CAN—Modbus智能网桥解决了线路传输距离影响信号质量以及Can总线收发器造成的回路中节点数受限制,同时解决上下层控制设备的协议兼容问题。本文采用LPC2294实现了Can—Modbus网桥,实现了协议转换;扩大了CAN网络的规模,延长了现场总线的长度。     

恶劣环境下互联网通信接口自适应转换系统设计

针对采用当前转换系统时一直存在通信接口转换效率低的问题,提出一种互联网通信接口转换系统设计方法。首先对恶劣环境下互联网通信接口自适应转换系统硬件平台进行设计,中央处理器与可编程逻辑门阵列间的接口部分主要负责控制通信转换,网络控制芯片与可编程逻辑门阵列间的接口部分负责以太网数据与网络通信总线数据转换,异步收发传输器接口部分负责通信数据转换。构建具有通信读写控制信号功能的分布式区域异步的存储器。软件平台设计从通信线速上对网络通信转换进行分析,给出互联网通信接口自适应转换系统应满足的约束条件,在该约束条件下以间断方式进行数据转换,完成对恶劣环境下互联网通信接口自适应转换系统设计。实验结果表明,该方法有效地提高恶劣环境下互联网网络的通信性能,降低网络通信能耗。     

基于现场总线的异步串行通信接口转换系统设计

传统异步串行通信接口转换系统转换过程中,CPU利用率差,转换的数据可靠性不高。为了解决上述问题,基于现场总线设计了一种新的异步串行通信接口转换系统。针对系统硬件和软件进行设计,利用核心控制模块、CAN总线通信接口、PROFIBUS-DP总线通信接口模块、异步串行通信接口转换模块、电源转换模块和总线选择开关模块构成硬件结构,在总架构的基础上给出了拓扑结构,重点设计了核心控制模块和PROFIBUS-DP总线通信接口模块。在硬件结构基础上设计软件程序,并在程序模块基础上研究了软件转换流程。为检测系统性能,设计对比实验,结果表明,基于现场总线设计的异步串行通信接口转换系统能够准确地转换出数据,确保结果的可靠性,CPU利用率高于传统系统。     

基于CAN总线的某通信系统应用层协议的设计与实现

以CAN2.0A为基础,通过安装在PC机上的内置SJA1000 CAN(控制器局域网)控制器的CAN总线通信接口卡实现CAN总线与PC机的通信,通过CAN总线通信接口卡函数实现自己制定的应用层协议。该协议根据某通信系统需要及CAN滤波方式,确定了信息ID(标识符)的分配,定义了报文传输格式。文中分析了单双滤波对本系统报文接收的影响,验证了本协议的可行性及合理性,最后给出本协议多帧数据传输的编程实现。     

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.