The PL2303 USB to Serial adapter is your smart and convenient accessory forconnecting RS-232 serial devices to your USB-equipped Windows host computer. Itprovides a bridge connection with a standard DB 9-pin male serial port connector inone end and a standard Type-A USB plug connector on the other end. You simplyattach the serial device onto the serial port of the cable and plug the USB connectorinto your PC USB port. It allows a simple and easy way of adding serial connectionsto your PC without having to go thru inserting a serial card and traditional portconfiguration.This USB to Serial adapter is ideal for connecting modems, cellular phones, PDAs,digital cameras, card readers and other serial devices to your computer. It providesserial connections up to 1Mbps of data transfer rate. And since USB does not requireany IRQ resource, more devices can be attached to the system without the previoushassles of device and resource conflicts.Finally, the PL-2303 USB to Serial adapter is a fully USB Specification compliantdevice and therefore supports advanced power management such as suspend andresume operations as well as remote wakeup. The PL-2303 USB Serial cable adapteris designed to work on all Windows operating systems.
（Portmon is an application that lets you monitor serial and parallel activity on your local system, or any computer on the network that you can reach via TCP/IP. It is the most powerful tool available for tracking down port-related configuration problems and analyzing application port usage.）
針對(duì)運(yùn)行中火車測速運(yùn)用多普勒效應(yīng)采用DSP 設(shè)計(jì)雷達(dá)測速系統(tǒng)并闡述了其基本設(shè)計(jì)思想與工作原理給出系統(tǒng)硬件軟件設(shè)計(jì)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(shí)驗(yàn)證明DSP 采集板工作穩(wěn)定測速效果好關(guān)鍵詞DSP; 雷達(dá)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
1 Communication Protocol (Computer as master)
The communication protocol describes here allows your computer to access 4096 internal registers (W0000-W4095) and 1024 internal relays (B0000-B1023) in the Workstation..
1.1 Request Message Format
Request message is a command message to be sent from the computer to the Workstation. The data structure of request message is shown below. Note that numbers are always in hexadecimal form and converted into ASCII characters. For example, Workstation unit number 14 will appear in the message as character 0(30h) followed by character E(45h); a BCC of 5Ah will appear in the message as character 5(35h) followed by character A(41h).
The field of microelectromechanical systems (MEMS), particularly micromachinedmechanical transducers, has been expanding over recent years, and the productioncosts of these devices continue to fall. Using materials, fabrication processes, anddesign tools originally developed for the microelectronic circuits industry, newtypes of microengineered device are evolving all the time—many offering numerousadvantages over their traditional counterparts. The electrical properties of siliconhave been well understood for many years, but it is the mechanical properties thathave been exploited in many examples of MEMS. This book may seem slightlyunusual in that it has four editors. However, since we all work together in this fieldwithin the School of Electronics and Computer Science at the University of Southampton,it seemed natural to work together on a project like this. MEMS are nowappearing as part of the syllabus for both undergraduate and postgraduate coursesat many universities, and we hope that this book will complement the teaching thatis taking place in this area.
本文主要通過介紹PLC通訊的意義和三菱FX系列PLC的四種通訊方式，并重點(diǎn)介紹FX系列PLC與計(jì)算機(jī)無協(xié)議通訊，主要從無協(xié)議通訊的硬件、配線、數(shù)據(jù)寄存器設(shè)置、PLC與計(jì)算機(jī)無協(xié)議通訊的指令用法、PLC程序編寫和計(jì)算機(jī)VB程序的編寫來說明無協(xié)議通訊的過程和一般方法。
My dissertation introduces the significance of PLC communications and the four means of communication of Mitsubishi FX’s PLC, And highlights the no protocol communications of FX series PLC and computer, no protocol communications hardware, wiring, Register data set, and the usage of command about no protocol communications, How to write PLC program and computer VB program to illustrate the process of no protocol communications and general method.
A Computer-On-Module, or COM, is a Module with all components necessary for a bootable host computer, packaged as a super component. A COM requires a Carrier Board to bring out I/O and to power up. COMs are used to build single board computer solutions and offer OEMs fast time-to-market with reduced development cost. Like integrated circuits, they provide OEMs with significant freedom in meeting form-fit-function requirements. For all these reasons the COM methodology has gained much popularity with OEMs in the embedded industry. COM Express® is an open industry standard for Computer-On-Modules. It is designed to be future proof and to provide a smooth transition path from legacy parallel interfaces to LVDS (Low Voltage Differential Signaling) interfaces. These include the PCI bus and parallel ATA on the one hand and PCI Express and Serial ATA on the other hand.
基于通用集成運(yùn)算放大器，利用MASON公式設(shè)計(jì)了一個(gè)多功能二階通用濾波器，能同時(shí)或分別實(shí)現(xiàn)低通、高通和帶通濾波，也能設(shè)計(jì)成一個(gè)正交振蕩器。電路的極點(diǎn)頻率和品質(zhì)因數(shù)能夠獨(dú)立、精確地調(diào)節(jié)。電路使用4個(gè)集成運(yùn)放、2個(gè)電容和11個(gè)電阻，所有集成運(yùn)放的反相端虛地。利用計(jì)算機(jī)仿真電路的通用濾波功能、極點(diǎn)頻率和品質(zhì)因數(shù)的獨(dú)立控制和正交正弦振蕩，從而證明該濾波器正確有效。
Abstract:
A new multifunctional second-order filter based on OPs was presented by MASON formula. Functions， such as high-pass， band-pass， low-pass filtering， can be realized respectively and simultaneously， and can become a quadrature oscillator by modifying resistance ratio. Its pole angular frequency and quality factor can be tuned accurately and independently. The circuit presented contains four OPs， two capacitors， and eleven resistances， and inverting input of all OPs is virtual ground. Its general filtering， the independent control of pole frequency and quality factor and quadrature sinusoidal oscillation were simulated by computer， and the result shows that the presented circuit is valid and effective.
