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： 2013-11-14
上傳用戶：zoudejile
最新的HDMI I.3（高清晰度多媒體接口1.3）標(biāo)準(zhǔn)把以前的HDMI 1.0 - 1.2標(biāo)準(zhǔn)所規(guī)定的數(shù)據(jù)傳送速度提高了一倍，每對差動信號線的速度達(dá)到3.4 Gbps。由于數(shù)據(jù)傳送速度這么高，要求電路板的電容小，確保信號的素質(zhì)很好，這給電路板的設(shè)計(jì)帶來了新的挑戰(zhàn)。在解決這個問題，實(shí)現(xiàn)可靠的靜電放電（ESD）保護(hù)時，這點(diǎn)尤其重要。在HDMI系統(tǒng)設(shè)計(jì)中增加ESD保護(hù)時，如果選用合適的辦法，就可以把問題簡化。泰科電子的ESD和過電流保護(hù)參考設(shè)計(jì)，符合3.4 GHz的HDMI 1.3規(guī)范，達(dá)到iec 61000-4-2關(guān)于ESD保護(hù)的要求，并且可以優(yōu)化電路板的空間，所有這些可以幫助設(shè)計(jì)人員減少風(fēng)險(xiǎn)。本文探討在HDMI 1.3系統(tǒng)中設(shè)計(jì)ESD保護(hù)的要求和容易犯的錯誤。 概述 在高清晰度視頻系統(tǒng)中增加ESD保護(hù)，提出了許多復(fù)雜而且令人為難的問題，這會增加成本，會延長產(chǎn)品上市的時間。人們在選擇ESD保護(hù)方案時，往往是根據(jù)解決這個問題的辦法實(shí)現(xiàn)起來是否容易。不過，最簡單的辦法也許不可能提供充分的ESD保護(hù)，或者在電路板上占用的空間不能讓人最滿意。有些時候，在開始時看上去是解決ESD保護(hù)問題的最好辦法，到了后來，會發(fā)現(xiàn)需要使用多種電路板材來保證時基信號達(dá)到要求。在實(shí)現(xiàn)一個充分的靜電放電保護(hù)時，往往需要在尺寸、靜電放電保護(hù)的性能以及實(shí)現(xiàn)起來是否容易這幾方面進(jìn)行折衷。一直到現(xiàn)在仍然是這樣。
標(biāo)簽： ESD 保護(hù)技術(shù) 白皮書
上傳時間： 2015-01-02
上傳用戶：zhuimenghuadie
微電腦型單相交流集合式電表（單相二線系統(tǒng)） 特點(diǎn)： 精確度0.25%滿刻度±1位數(shù) 可同時量測與顯示交流電壓,電流,頻率,瓦特,(功率因數(shù)/視在功率) 交流電壓,電流,瓦特皆為真正有效值(TRMS) 交流電流,瓦特之小數(shù)點(diǎn)可任意設(shè)定 瓦特單位W或KW可任意設(shè)定 CT比可任意設(shè)定(1至999) 輸入與輸出絕緣耐壓 2仟伏特/1分鐘( 突波測試強(qiáng)度4仟伏特(1.2x50us) 數(shù)位RS-485界面 (Optional) 主要規(guī)格： 精確度: 0.1% F.S.±1 digit (Frequency) 0.25% F.S.±1 digit(ACA,ACV,Watt,VA) 0.25% F.S. ±0.25o(Power Factor) (-.300~+.300) 輸入負(fù)載: <0.2VA (Voltage) <0.2VA (Current) 最大過載能力: Current related input: 3 x rated continuous 10 x rated 30 sec. 25 x rated 3sec. 50 x rated 1sec. Voltage related input: maximum 2 x rated continuous 過載顯示: "doFL" 顯示值范圍: 0~600.0V(Voltage) 0~999.9Hz(Frequency)(<20% for voltage input) 0~19999 digit adjustable(Current,Watt,VA) 取樣時間: 2 cycles/sec. RS-485通訊位址: "01"-"FF" RS-485傳輸速度: 19200/9600/4800/2400 selective RS-485通信協(xié)議: Modbus RTU mode 溫度系數(shù): 100ppm/℃ (0-50℃) 顯示幕: Red high efficiency LEDs high 10.16 mm(0.4") 參數(shù)設(shè)定方式: Touch switches 記憶型式: Non-volatile E²PROM memory 絕緣抗阻: >100Mohm with 500V DC 絕緣耐壓能力: 2KVac/1 min. (input/output/power) 1600 Vdc (input/output) 突波測試: ANSI c37.90a/1974,DIN-iec 255-4 impulse voltage 4KV(1.2x50us) 使用環(huán)境條件: 0-50℃(20 to 90% RH non-condensed) 存放環(huán)境條件: 0-70℃(20 to 90% RH non-condensed) CE認(rèn)證: EN 55022:1998/A1:2000 Class A EN 61000-3-2:2000 EN 61000-3-3:1995/A1:2001 EN 55024:1998/A1:2001
上傳時間： 2015-01-03
上傳用戶：幾何公差
在強(qiáng)調(diào)正確性、可移植性和可維護(hù)性的基礎(chǔ)上，對C語言的具體細(xì)節(jié)、運(yùn)行庫以及C語言編程風(fēng)格做了完整、準(zhǔn)確的描述。本書涵蓋了傳統(tǒng)C語言、C89、C95、C99等所有C語言版本的實(shí)現(xiàn)，同時討論了C++與C語言兼容的部分。全書自上而下介紹了C語言的詞法結(jié)構(gòu)、預(yù)處理器、聲明、類型表達(dá)式、語句、函數(shù)和運(yùn)行庫，是所有C語言編程人員必備的參考書。 這本暢銷的權(quán)威參考手冊對C語言的基本概念和運(yùn)行庫提供了完整的描述，同時還強(qiáng)調(diào)了以正確性、可移植性和可維護(hù)性為根本出發(fā)點(diǎn)的良好的C語言編程風(fēng)格，被國外眾多高校廣泛采用為教材或教學(xué)參考書，本書描述了C語言各個版本的所有細(xì)節(jié)，是C語言編程人員和實(shí)現(xiàn)者惟一必備的參考手冊。最新的第5版經(jīng)過修訂和更新，融入了最新C語言標(biāo)準(zhǔn)ISO iec 9899：1999的完整描述，包括強(qiáng)大的語言擴(kuò)展和新的函數(shù)庫。
上傳時間： 2014-01-21
上傳用戶：xz85592677
INTERNATIONAL ORGANISATION FOR STANDARDISATION ORGANISATION INTERNATIONALE DE NORMALISATION ISO/iec JTC1/SC29/WG11 CODING OF MOVING PICTURES AND AUDIO
標(biāo)簽： ORGANISATION STANDARDISATION INTERNATIONALE INTERNATIONAL
上傳時間： 2014-01-11
上傳用戶：ainimao
DIGITAL IMAGERY is pervasive in our world today. Consequently, standards for the efficient representation and interchange of digital images are essential. To date, some of the most successful still image compression standards have resulted from the ongoing work of the Joint Photographic Experts Group (JPEG). This group operates under the auspices of Joint Technical Committee 1, Subcommittee 29, Working Group 1 (JTC 1/SC 29/WG 1), a collaborative effort between the International Organization for Standardization (ISO) and International Telecommunication Union Standardization Sector (ITUT). Both the JPEG [1–3] and JPEG-LS [4–6] standards were born from the work of the JPEG committee. For the last few years, the JPEG committee has been working towards the establishment of a new standard known as JPEG 2000 (i.e., ISO/iec 15444). The fruits of these labors are now coming to bear, as JPEG-2000 Part 1 (i.e., ISO/iec 15444-1 [7]) has recently been approved as a new international standard.
標(biāo)簽： Consequently efficient pervasive standards
上傳時間： 2013-12-21
上傳用戶：源弋弋
Draft ITU-T Recommendation and Final Draft International Standard of Joint Video Specification(ITU-T REec. H.264 | ISO/iec 14496-10 AVC).H.264視頻編碼標(biāo)準(zhǔn)的中文翻譯版本，由沈燕飛對原文作翻譯。
標(biāo)簽： Draft ITU-T Recommendation International
上傳時間： 2014-01-05
上傳用戶：來茴
Draft ITU-T Recommendation and Final Draft International Standard of Joint Video Specification(ITU-T Rec.H.264 | ISO/iec 14496-10 AVC) H.264編碼標(biāo)準(zhǔn)，主體部分是中英文對照
標(biāo)簽： Draft ITU-T Recommendation International
上傳時間： 2015-09-28
上傳用戶：lunshaomo
The Scalable Video Coding(SVC) draft specification version 8 was released by Joint Video Team(JVT) on Oct,2006. JVT is formed by ISO/iec MPEG & ITU-T VCEG.
標(biāo)簽： Video specification Scalable released
上傳時間： 2015-10-11
上傳用戶：924484786
三相短路電流計(jì)算方法的探討 呂文杰 ：利用PSS / E 程序豐富的短路電流計(jì)算功能和靈活的短路電流初值設(shè)置條件，分析了影響短路電流計(jì)算結(jié)果 的一些關(guān)鍵因素，對基于潮流的短路電流計(jì)算、經(jīng)典計(jì)算方法和iec 推薦方法進(jìn)行了比較
上傳時間： 2013-12-11
上傳用戶：colinal
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