-
Easy-to-use and compact point-of-load power suppliesare necessary in systems with widely Distributed, highcurrent, low voltage loads. The LTC®3415 provides acompact, simple and versatile solution. It includes a pairof integrated complementary power MOSFETs (32mΩtop and 25mΩ bottom) and requires no external senseresistor. A complete design requires an inductor andinput/output capacitors, and that’s it. The result is a fast,constant frequency, 7A current mode DC/DC switchingregulator.
標簽：
387
DN
級聯
負載
上傳時間：
2013-10-18
上傳用戶：avensy
-
Permission to make digital or hard copies of all or part of this work forpersonal or classroom use is granted without fee provided that copies arenot made or Distributed for profit or commercial advantage and that copiesbear this notice and the full citation on the first page. To copy otherwise, torepublish, to post on servers or to redistribute to lists, requires prior specificpermission.
標簽：
數字電源
上傳時間：
2013-10-16
上傳用戶：dddddd
-
闡述了一個由上位PC機和AT89C52下位單片機組成的主從分布式溫度巡回檢測系統。主從機采用RS-485 串行通訊標準進行通信，可在下位單片機實現基本的溫度數據巡回檢測基礎上，由上位PC機實現綜合處理功能或擴展為遠程操作。整個系統具有巡檢速度快，擴展性好的特點。
Abstract:
In this paper,a top PC and AT89C52 under-bit microcontrollers from the main component of the tour Distributed temperature detection system is presented. Master and slave can use RS-485 serial communication standards for communications.Based on next-bit machine for basic goods temperature detected data Tour, the top can achieve the integrated treatment of PC functions or for the expansion of long-distance operation. The entire inspection system is fast, expansion.
標簽：
89C
C52
AT
89
上傳時間：
2013-10-13
上傳用戶：zhoujunzhen
-
一種實用的微機自動配料秤系統:介紹一種由單片機構成的配料秤。敘述了秤的傳感器、變送器、信號的變換、硬件原理、軟件流程以及和DCS 系統構成的單回路調節系統,此系統可廣泛地應用于各行業的配料控制中。關鍵詞:配料秤 單片機 單回路調節系統 DCS 系統
Abstract :A proportioning weigher based on single chip computer is introduced. Sensors , transmitters , signal converting , principle of hardware ,software flowchart of proportioning weigher and single loop control system composed with DCS system are emphasized ,this system can be used in proportioning control of various trades extensively.Key Words :Proportioning Weigher ,Single Chip Computer ,Single Loop Control System ,Distributed Control System
標簽：
微機
自動
配料秤
上傳時間：
2013-10-12
上傳用戶：zwei41
-
This white paper discusses how market trends, the need for increased productivity, and new legislation have
accelerated the use of safety systems in industrial machinery. This TÜV-qualified FPGA design methodology is
changing the paradigms of safety designs and will greatly reduce development effort, system complexity, and time to
market. This allows FPGA users to design their own customized safety controllers and provides a significant
competitive advantage over traditional microcontroller or ASIC-based designs.
Introduction
The basic motivation of deploying functional safety systems is to ensure safe operation as well as safe behavior in
cases of failure. Examples of functional safety systems include train brakes, proximity sensors for hazardous areas
around machines such as fast-moving robots, and Distributed control systems in process automation equipment such
as those used in petrochemical plants.
The International Electrotechnical Commission’s standard, IEC 61508: “Functional safety of
electrical/electronic/programmable electronic safety-related systems,” is understood as the standard for designing
safety systems for electrical, electronic, and programmable electronic (E/E/PE) equipment. This standard was
developed in the mid-1980s and has been revised several times to cover the technical advances in various industries.
In addition, derivative standards have been developed for specific markets and applications that prescribe the
particular requirements on functional safety systems in these industry applications. Example applications include
process automation (IEC 61511), machine automation (IEC 62061), transportation (railway EN 50128), medical (IEC
62304), automotive (ISO 26262), power generation, distribution, and transportation.
圖Figure 1. Local Safety System
標簽：
FPGA
安全系統
上傳時間：
2013-11-05
上傳用戶：維子哥哥
-
USB接口控制器參考設計,xilinx提供VHDL代碼 usb xilinx vhdl
; This program is free software; you can redistribute it and/or modify
; it under the terms of the GNU General Public License as published by
; the Free Software Foundation; either version 2 of the License, or
; (at your option) any later version.
;
; This program is Distributed in the hope that it will be useful,
; but WITHOUT ANY WARRANTY; without even the implied warranty of
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
; GNU General Public License for more details.
;
; You should have received a copy of the GNU General Public License
; along with this program; if not, write to the Free Software
; Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
標簽：
xilinx
VHDL
USB
us
上傳時間：
2013-10-12
上傳用戶：windgate
-
很多不同的廠家生產各種型號的計算機，它們運行完全不同的操作系統，但TCP.IP協議族允許它們互相進行通信。這一點很讓人感到吃驚，因為它的作用已遠遠超出了起初的設想。T C P / I P起源于6 0年代末美國政府資助的一個分組交換網絡研究項目，到9 0年代已發展成為計算機之間最常應用的組網形式。它是一個真正的開放系統，因為協議族的定義及其多種實現可以不用花錢或花很少的錢就可以公開地得到。它成為被稱作“全球互聯網”或“因特網(Internet)”的基礎，該廣域網（WA N）已包含超過1 0 0萬臺遍布世界各地的計算機。本章主要對T C P / I P協議族進行概述，其目的是為本書其余章節提供充分的背景知識。
TCP.IP協議 縮略語
ACK (ACKnowledgment) TCP首部中的確認標志
API (Application Programming Interface) 應用編程接口
ARP (Address Resolution Protocol) 地址解析協議
ARPANET(Defense Advanced Research Project Agency NETwork) (美國)國防部遠景研究規劃局
AS (Autonomous System) 自治系統
ASCII (American Standard Code for Information Interchange) 美國信息交換標準碼
ASN.1 (Abstract Syntax Notation One) 抽象語法記法1
BER (Basic Encoding Rule) 基本編碼規則
BGP (Border Gateway Protocol) 邊界網關協議
BIND (Berkeley Internet Name Domain) 伯克利I n t e r n e t域名
BOOTP (BOOTstrap Protocol) 引導程序協議
BPF (BSD Packet Filter) BSD 分組過濾器
CIDR (Classless InterDomain Routing) 無類型域間選路
CIX (Commercial Internet Exchange) 商業互聯網交換
CLNP (ConnectionLess Network Protocol) 無連接網絡協議
CRC (Cyclic Redundancy Check) 循環冗余檢驗
CSLIP (Compressed SLIP) 壓縮的S L I P
CSMA (Carrier Sense Multiple Access) 載波偵聽多路存取
DCE (Data Circuit-terminating Equipment) 數據電路端接設備
DDN (Defense Data Network) 國防數據網
DF (Don’t Fragment) IP首部中的不分片標志
DHCP (Dynamic Host Configuration Protocol) 動態主機配置協議
DLPI (Data Link Provider Interface) 數據鏈路提供者接口
DNS (Domain Name System) 域名系統
DSAP (Destination Service Access Point) 目的服務訪問點
DSLAM (DSL Access Multiplexer) 數字用戶線接入復用器
DSSS (Direct Sequence Spread Spectrum) 直接序列擴頻
DTS (Distributed Time Service) 分布式時間服務
DVMRP (Distance Vector Multicast Routing Protocol) 距離向量多播選路協議
EBONE (European IP BackbONE) 歐洲I P主干網
EOL (End of Option List) 選項清單結束
EGP (External Gateway Protocol) 外部網關協議
EIA (Electronic Industries Association) 美國電子工業協會
FCS (Frame Check Sequence) 幀檢驗序列
FDDI (Fiber Distributed Data Interface) 光纖分布式數據接口
FIFO (First In, First Out) 先進先出
FIN (FINish) TCP首部中的結束標志
FQDN (Full Qualified Domain Name) 完全合格的域名
FTP (File Transfer Protocol) 文件傳送協議
HDLC (High-level Data Link Control) 高級數據鏈路控制
HELLO 選路協議
IAB (Internet Architecture Board) Internet體系結構委員會
IANA (Internet Assigned Numbers Authority) Internet號分配機構
ICMP (Internet Control Message Protocol) Internet控制報文協議
IDRP (InterDomain Routing Protocol) 域間選路協議
IEEE (Institute of Electrical and Electronics Engineering) （美國）電氣與電子工程師協會
IEN (Internet Experiment Notes) 互聯網試驗注釋
IESG (Internet Engineering Steering Group) Internet工程指導小組
IETF (Internet Engineering Task Force) Internet工程專門小組
IGMP (Internet Group Management Protocol) Internet組管理協議
IGP (Interior Gateway Protocol) 內部網關協議
IMAP (Internet Message Access Protocol) Internet報文存取協議
IP (Internet Protocol) 網際協議
I RTF (Internet Research Task Force) Internet研究專門小組
IS-IS (Intermediate System to Intermediate System Protocol) 中間系統到中間系統協議
ISN (Initial Sequence Number) 初始序號
ISO (International Organization for Standardization) 國際標準化組織
ISOC (Internet SOCiety) Internet協會
LAN (Local Area Network) 局域網
LBX (Low Bandwidth X) 低帶寬X
LCP (Link Control Protocol) 鏈路控制協議
LFN (Long Fat Net) 長肥網絡
LIFO (Last In, First Out) 后進先出
LLC (Logical Link Control) 邏輯鏈路控制
LSRR (Loose Source and Record Route) 寬松的源站及記錄路由
MBONE (Multicast Backbone On the InterNEt) Internet上的多播主干網
MIB (Management Information Base) 管理信息庫
MILNET (MILitary NETwork) 軍用網
MIME (Multipurpose Internet Mail Extensions) 通用I n t e r n e t郵件擴充
MSL (Maximum Segment Lifetime) 報文段最大生存時間
MSS (Maximum Segment Size) 最大報文段長度
M TA (Message Transfer Agent) 報文傳送代理
MTU (Maximum Transmission Unit) 最大傳輸單元
NCP (Network Control Protocol) 網絡控制協議
NFS (Network File System) 網絡文件系統
NIC (Network Information Center) 網絡信息中心
NIT (Network Interface Tap) 網絡接口栓（S u n公司的一個程序）
NNTP (Network News Transfer Protocol) 網絡新聞傳送協議
NOAO (National Optical Astronomy Observatories) 國家光學天文臺
NOP (No Operation) 無操作
NSFNET (National Science Foundation NETwork) 國家科學基金網絡
NSI (NASA Science Internet) （美國）國家宇航局I n t e r n e t
NTP (Network Time Protocol) 網絡時間協議
NVT (Network Virtual Terminal) 網絡虛擬終端
OSF (Open Software Foudation) 開放軟件基金
OSI (Open Systems Interconnection) 開放系統互連
OSPF (Open Shortest Path First) 開放最短通路優先
PAWS (Protection Against Wrapped Sequence number) 防止回繞的序號
PDU (Protocol Data Unit) 協議數據單元
POSIX (Portable Operating System Interface) 可移植操作系統接口
PPP (Point-to-Point Protocol) 點對點協議
PSH (PuSH) TCP首部中的急迫標志
RARP (Reverse Address Resolution Protocol) 逆地址解析協議
RFC (Request For Comments) Internet的文檔，其中的少部分成為標準文檔
RIP (Routing Information Protocol) 路由信息協議
RPC (Remote Procedure Call) 遠程過程調用
RR (Resource Record) 資源記錄
RST (ReSeT) TCP首部中的復位標志
RTO (Retransmission Time Out) 重傳超時
RTT (Round-Trip Time) 往返時間
SACK (Selective ACKnowledgment) 有選擇的確認
SLIP (Serial Line Internet Protocol) 串行線路I n t e r n e t協議
SMI (Structure of Management Information) 管理信息結構
SMTP (Simple Mail Transfer Protocol) 簡單郵件傳送協議
SNMP (Simple Network Management Protocol) 簡單網絡管理協議
SSAP (Source Service Access Point) 源服務訪問點
SSRR (Strict Source and Record Route) 嚴格的源站及記錄路由
SWS (Silly Window Syndrome) 糊涂窗口綜合癥
SYN (SYNchronous) TCP首部中的同步序號標志
TCP (Transmission Control Protocol) 傳輸控制協議
TFTP (Trivial File Transfer Protocol) 簡單文件傳送協議
TLI (Transport Layer Interface) 運輸層接口
TTL (Ti m e - To-Live) 生存時間或壽命
TUBA (TCP and UDP with Bigger Addresses) 具有更長地址的T C P和U D P
Telnet 遠程終端協議
UA (User Agent) 用戶代理
UDP (User Datagram Protocol) 用戶數據報協議
URG (URGent) TCP首部中的緊急指針標志
UTC (Coordinated Universal Time) 協調的統一時間
UUCP (Unix-to-Unix CoPy) Unix到U n i x的復制
WAN (Wide Area Network) 廣域網
WWW (World Wide Web) 萬維網
XDR (eXternal Data Representation) 外部數據表示
XID (transaction ID) 事務標識符
XTI (X/Open Transport Layer Interface) X/ O p e n運輸層接口
標簽：
tcp
協議
上傳時間：
2013-11-13
上傳用戶：tdyoung
-
鑒于目前多數水廠采用的是基于PLC的集散式（DCS，Distributed Control System）控制模式。目的在于研究一種采用現場總線技術構建水廠控制網絡的方法。這里選用的是Echelon公司推出的LonWorks技術，用來構建水廠全分布式管控一體化的網絡體系，涉及現場智能節點的功能與設置、現場控制網絡的構建和上層管控系統的功能與實現，可供同類企業設計時參考。
標簽：
LonWorks
分布
管控一體化網絡
上傳時間：
2014-11-28
上傳用戶：takako_yang
-
Single-Ended and Differential S-Parameters
Differential circuits have been important incommunication systems for many years. In the past,differential communication circuits operated at lowfrequencies, where they could be designed andanalyzed using lumped-element models andtechniques. With the frequency of operationincreasing beyond 1GHz, and above 1Gbps fordigital communications, this lumped-elementapproach is no longer valid, because the physicalsize of the circuit approaches the size of awavelength.Distributed models and analysis techniques are nowused instead of lumped-element techniques.Scattering parameters, or S-parameters, have beendeveloped for this purpose [1]. These S-parametersare defined for single-ended networks. S-parameterscan be used to describe differential networks, but astrict definition was not developed until Bockelmanand others addressed this issue [2]. Bockelman’swork also included a study on how to adapt single-ended S-parameters for use with differential circuits[2]. This adaptation, called “mixed-mode S-parameters,” addresses differential and common-mode operation, as well as the conversion betweenthe two modes of operation.This application note will explain the use of single-ended and mixed-mode S-parameters, and the basicconcepts of microwave measurement calibration.
標簽：
差分電路
單端
模式
上傳時間：
2014-03-25
上傳用戶：yyyyyyyyyy
-
3dmax9.0 — 全世界最知名的3D動畫制作軟件 ，最新版本 3dmax9.0 已經于去年7月底在圣地牙哥正式發布了！3dmax9.0一直在動畫市場上占有非常重要的地位，尤其在電影特效、游戲軟件開發的領域里，discreet不斷在改造出更具強大功能與相容性的軟件來迎接這個新的視覺傳播世代。 你可以在3dmax9.0最新版中，看到3dmax9.0如何幫助設計師與動畫師更精準的掌握動畫背景與人物結構，同時呈現出每個角色震撼的生命力.。 3dmax9.0 根據包括SEGA在內用戶的要求，加強了游戲和電影特效的功能。 3dmax9.0 部分新功能如下：高級列表功能，查看和管理復雜場景。新軟件包括了新的mental ray渲染器和可視工具。對Autodesk的CAD支持更好。分布式網絡材質成型。創建現實的霧、雪、噴泉、彈著點等的質點流量系統。 3dmax9.0 新功能將包括： 高級瀏覽器，可以隨時觀看圖片文件和max文件； 復雜的場景管理器用來管理大的場景； 整合的mental ray渲染器可以渲染出非常高質量的圖片和動畫、 頂點顏色繪制（vertex color painting）； design visualization tools； 支持CAD、 動力學版本是reactor 2 ； Distributed network texture baking； 3dmax9.0還增加了一些材質并整合了部分舊版本中常用的材質。除此之外，3dmax9.0為mental ray渲染器增添了多種材質。包括：DGS Material（physics_phen）、Glass（physics_phen）和mental ray 總的來說3dmax9.0的功能非常強大。
標簽：
max
9.0
3d
上傳時間：
2013-10-22
上傳用戶：181992417
