-
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(biāo)簽：
387
DN
級聯(lián)
負(fù)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(biāo)簽：
數(shù)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(jī)和AT89C52下位單片機(jī)組成的主從分布式溫度巡回檢測系統(tǒng)。主從機(jī)采用RS-485 串行通訊標(biāo)準(zhǔn)進(jìn)行通信，可在下位單片機(jī)實現(xiàn)基本的溫度數(shù)據(jù)巡回檢測基礎(chǔ)上，由上位PC機(jī)實現(xiàn)綜合處理功能或擴(kuò)展為遠(yuǎn)程操作。整個系統(tǒng)具有巡檢速度快，擴(kuò)展性好的特點(diǎn)。
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(biāo)簽：
89C
C52
AT
89
上傳時間：
2013-10-13
上傳用戶：zhoujunzhen
-
一種實用的微機(jī)自動配料秤系統(tǒng):介紹一種由單片機(jī)構(gòu)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(tǒng)構(gòu)成的單回路調(diào)節(jié)系統(tǒng),此系統(tǒng)可廣泛地應(yīng)用于各行業(yè)的配料控制中。關(guān)鍵詞:配料秤 單片機(jī) 單回路調(diào)節(jié)系統(tǒng) DCS 系統(tǒng)
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(biāo)簽：
微機(jī)
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(biāo)簽：
FPGA
安全系統(tǒng)
上傳時間：
2013-11-05
上傳用戶：維子哥哥
-
USB接口控制器參考設(shè)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(biāo)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(chǎn)各種型號的計算機(jī)，它們運(yùn)行完全不同的操作系統(tǒng)，但TCP.IP協(xié)議族允許它們互相進(jìn)行通信。這一點(diǎn)很讓人感到吃驚，因為它的作用已遠(yuǎn)遠(yuǎn)超出了起初的設(shè)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(wǎng)絡(luò)研究項目，到9 0年代已發(fā)展成為計算機(jī)之間最常應(yīng)用的組網(wǎng)形式。它是一個真正的開放系統(tǒng)，因為協(xié)議族的定義及其多種實現(xiàn)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(lián)網(wǎng)”或“因特網(wǎng)(Internet)”的基礎(chǔ)，該廣域網(wǎng)（WA N）已包含超過1 0 0萬臺遍布世界各地的計算機(jī)。本章主要對T C P / I P協(xié)議族進(jìn)行概述，其目的是為本書其余章節(jié)提供充分的背景知識。
TCP.IP協(xié)議 縮略語
ACK (ACKnowledgment) TCP首部中的確認(rèn)標(biāo)志
API (Application Programming Interface) 應(yīng)用編程接口
ARP (Address Resolution Protocol) 地址解析協(xié)議
ARPANET(Defense Advanced Research Project Agency NETwork) (美國)國防部遠(yuǎn)景研究規(guī)劃局
AS (Autonomous System) 自治系統(tǒng)
ASCII (American Standard Code for Information Interchange) 美國信息交換標(biāo)準(zhǔn)碼
ASN.1 (Abstract Syntax Notation One) 抽象語法記法1
BER (Basic Encoding Rule) 基本編碼規(guī)則
BGP (Border Gateway Protocol) 邊界網(wǎng)關(guān)協(xié)議
BIND (Berkeley Internet Name Domain) 伯克利I n t e r n e t域名
BOOTP (BOOTstrap Protocol) 引導(dǎo)程序協(xié)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(yè)互聯(lián)網(wǎng)交換
CLNP (ConnectionLess Network Protocol) 無連接網(wǎng)絡(luò)協(xié)議
CRC (Cyclic Redundancy Check) 循環(huán)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(shù)據(jù)電路端接設(shè)備
DDN (Defense Data Network) 國防數(shù)據(jù)網(wǎng)
DF (Don’t Fragment) IP首部中的不分片標(biāo)志
DHCP (Dynamic Host Configuration Protocol) 動態(tài)主機(jī)配置協(xié)議
DLPI (Data Link Provider Interface) 數(shù)據(jù)鏈路提供者接口
DNS (Domain Name System) 域名系統(tǒng)
DSAP (Destination Service Access Point) 目的服務(wù)訪問點(diǎn)
DSLAM (DSL Access Multiplexer) 數(shù)字用戶線接入復(fù)用器
DSSS (Direct Sequence Spread Spectrum) 直接序列擴(kuò)頻
DTS (DISTRIBUTED Time Service) 分布式時間服務(wù)
DVMRP (Distance Vector Multicast Routing Protocol) 距離向量多播選路協(xié)議
EBONE (European IP BackbONE) 歐洲I P主干網(wǎng)
EOL (End of Option List) 選項清單結(jié)束
EGP (External Gateway Protocol) 外部網(wǎng)關(guān)協(xié)議
EIA (Electronic Industries Association) 美國電子工業(yè)協(xié)會
FCS (Frame Check Sequence) 幀檢驗序列
FDDI (Fiber DISTRIBUTED Data Interface) 光纖分布式數(shù)據(jù)接口
FIFO (First In, First Out) 先進(jìn)先出
FIN (FINish) TCP首部中的結(jié)束標(biāo)志
FQDN (Full Qualified Domain Name) 完全合格的域名
FTP (File Transfer Protocol) 文件傳送協(xié)議
HDLC (High-level Data Link Control) 高級數(shù)據(jù)鏈路控制
HELLO 選路協(xié)議
IAB (Internet Architecture Board) Internet體系結(jié)構(gòu)委員會
IANA (Internet Assigned Numbers Authority) Internet號分配機(jī)構(gòu)
ICMP (Internet Control Message Protocol) Internet控制報文協(xié)議
IDRP (InterDomain Routing Protocol) 域間選路協(xié)議
IEEE (Institute of Electrical and Electronics Engineering) （美國）電氣與電子工程師協(xié)會
IEN (Internet Experiment Notes) 互聯(lián)網(wǎng)試驗注釋
IESG (Internet Engineering Steering Group) Internet工程指導(dǎo)小組
IETF (Internet Engineering Task Force) Internet工程專門小組
IGMP (Internet Group Management Protocol) Internet組管理協(xié)議
IGP (Interior Gateway Protocol) 內(nèi)部網(wǎng)關(guān)協(xié)議
IMAP (Internet Message Access Protocol) Internet報文存取協(xié)議
IP (Internet Protocol) 網(wǎng)際協(xié)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(tǒng)到中間系統(tǒng)協(xié)議
ISN (Initial Sequence Number) 初始序號
ISO (International Organization for Standardization) 國際標(biāo)準(zhǔn)化組織
ISOC (Internet SOCiety) Internet協(xié)會
LAN (Local Area Network) 局域網(wǎng)
LBX (Low Bandwidth X) 低帶寬X
LCP (Link Control Protocol) 鏈路控制協(xié)議
LFN (Long Fat Net) 長肥網(wǎng)絡(luò)
LIFO (Last In, First Out) 后進(jìn)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(wǎng)
MIB (Management Information Base) 管理信息庫
MILNET (MILitary NETwork) 軍用網(wǎng)
MIME (Multipurpose Internet Mail Extensions) 通用I n t e r n e t郵件擴(kuò)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(wǎng)絡(luò)控制協(xié)議
NFS (Network File System) 網(wǎng)絡(luò)文件系統(tǒng)
NIC (Network Information Center) 網(wǎng)絡(luò)信息中心
NIT (Network Interface Tap) 網(wǎng)絡(luò)接口栓（S u n公司的一個程序）
NNTP (Network News Transfer Protocol) 網(wǎng)絡(luò)新聞傳送協(xié)議
NOAO (National Optical Astronomy Observatories) 國家光學(xué)天文臺
NOP (No Operation) 無操作
NSFNET (National Science Foundation NETwork) 國家科學(xué)基金網(wǎng)絡(luò)
NSI (NASA Science Internet) （美國）國家宇航局I n t e r n e t
NTP (Network Time Protocol) 網(wǎng)絡(luò)時間協(xié)議
NVT (Network Virtual Terminal) 網(wǎng)絡(luò)虛擬終端
OSF (Open Software Foudation) 開放軟件基金
OSI (Open Systems Interconnection) 開放系統(tǒng)互連
OSPF (Open Shortest Path First) 開放最短通路優(yōu)先
PAWS (Protection Against Wrapped Sequence number) 防止回繞的序號
PDU (Protocol Data Unit) 協(xié)議數(shù)據(jù)單元
POSIX (Portable Operating System Interface) 可移植操作系統(tǒng)接口
PPP (Point-to-Point Protocol) 點(diǎn)對點(diǎn)協(xié)議
PSH (PuSH) TCP首部中的急迫標(biāo)志
RARP (Reverse Address Resolution Protocol) 逆地址解析協(xié)議
RFC (Request For Comments) Internet的文檔，其中的少部分成為標(biāo)準(zhǔn)文檔
RIP (Routing Information Protocol) 路由信息協(xié)議
RPC (Remote Procedure Call) 遠(yuǎn)程過程調(diào)用
RR (Resource Record) 資源記錄
RST (ReSeT) TCP首部中的復(fù)位標(biāo)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(rèn)
SLIP (Serial Line Internet Protocol) 串行線路I n t e r n e t協(xié)議
SMI (Structure of Management Information) 管理信息結(jié)構(gòu)
SMTP (Simple Mail Transfer Protocol) 簡單郵件傳送協(xié)議
SNMP (Simple Network Management Protocol) 簡單網(wǎng)絡(luò)管理協(xié)議
SSAP (Source Service Access Point) 源服務(wù)訪問點(diǎn)
SSRR (Strict Source and Record Route) 嚴(yán)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(biāo)志
TCP (Transmission Control Protocol) 傳輸控制協(xié)議
TFTP (Trivial File Transfer Protocol) 簡單文件傳送協(xié)議
TLI (Transport Layer Interface) 運(yùn)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(yuǎn)程終端協(xié)議
UA (User Agent) 用戶代理
UDP (User Datagram Protocol) 用戶數(shù)據(jù)報協(xié)議
URG (URGent) TCP首部中的緊急指針標(biāo)志
UTC (Coordinated Universal Time) 協(xié)調(diào)的統(tǒng)一時間
UUCP (Unix-to-Unix CoPy) Unix到U n i x的復(fù)制
WAN (Wide Area Network) 廣域網(wǎng)
WWW (World Wide Web) 萬維網(wǎng)
XDR (eXternal Data Representation) 外部數(shù)據(jù)表示
XID (transaction ID) 事務(wù)標(biāo)識符
XTI (X/Open Transport Layer Interface) X/ O p e n運(yùn)輸層接口
標(biāo)簽：
tcp
協(xié)議
上傳時間：
2013-11-13
上傳用戶：tdyoung
-
鑒于目前多數(shù)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(xiàn)場總線技術(shù)構(gòu)建水廠控制網(wǎng)絡(luò)的方法。這里選用的是Echelon公司推出的LonWorks技術(shù)，用來構(gòu)建水廠全分布式管控一體化的網(wǎng)絡(luò)體系，涉及現(xiàn)場智能節(jié)點(diǎn)的功能與設(shè)置、現(xiàn)場控制網(wǎng)絡(luò)的構(gòu)建和上層管控系統(tǒng)的功能與實現(xiàn)，可供同類企業(yè)設(shè)計時參考。
標(biāo)簽：
LonWorks
分布
管控一體化網(wǎng)絡(luò)
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(biāo)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(jīng)于去年7月底在圣地牙哥正式發(fā)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(fā)的領(lǐng)域里，discreet不斷在改造出更具強(qiáng)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(shè)計師與動畫師更精準(zhǔn)的掌握動畫背景與人物結(jié)構(gòu)，同時呈現(xiàn)出每個角色震撼的生命力.。 3dmax9.0 根據(jù)包括SEGA在內(nèi)用戶的要求，加強(qiáng)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(fù)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(wǎng)絡(luò)材質(zhì)成型。創(chuàng)建現(xiàn)實的霧、雪、噴泉、彈著點(diǎn)等的質(zhì)點(diǎn)流量系統(tǒng)。 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(fù)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(zhì)量的圖片和動畫、 頂點(diǎn)顏色繪制（vertex color painting）； design visualization tools； 支持CAD、 動力學(xué)版本是reactor 2 ； DISTRIBUTED network texture baking； 3dmax9.0還增加了一些材質(zhì)并整合了部分舊版本中常用的材質(zhì)。除此之外，3dmax9.0為mental ray渲染器增添了多種材質(zhì)。包括：DGS Material（physics_phen）、Glass（physics_phen）和mental ray 總的來說3dmax9.0的功能非常強(qiáng)大。
標(biāo)簽：
max
9.0
3d
上傳時間：
2013-10-22
上傳用戶：181992417
