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  1. Programmable logic controller - Wikipedia

    en.wikipedia.org/wiki/Programmable_logic_controller
    • Invention and Early Development
    • Architecture
    • Programming
    • Functionality
    • Process of A Scan Cycle
    • Security
    • Safety PLCs
    • Plc Compared with Other Control Systems
    • See Also
    • Further Reading

    PLC originated in the late 1960s in the automotive industry in the US and were designed to replace relay logic systems. Before, control logic for manufacturing was mainly composed of relays, cam timers, drum sequencers, and dedicated closed-loop controllers. The hard-wired nature made it difficult for design engineers to alter the process. Changes would require rewiring and careful updating of the documentation. If even one wire were out of place, or one relay failed, the whole system would become faulty. Often technicians would spend hours troubleshooting by examining the schematics and comparing them to existing wiring. When general-purpose computers became available, they were soon applied to control logic in industrial processes. These early computers were unreliableand required specialist programmers and strict control of working conditions, such as temperature, cleanliness, and power quality. The PLC provided several advantages over earlier automation systems. It tolerated the...

    A PLC is an industrial microprocessor-based controller with programmable memory used to store program instructions and various functions.It consists of: 1. a processor unit (CPU) which interprets inputs, executes the control program stored in memory and sends output signals, 2. a power supply unit which converts AC voltage to DC, 3. a memory unit storing data from inputs and program to be executed by the processor, 4. an input and output interface, where the controller receives and sends data from/to external devices, 5. a communications interface to receive and transmit data on communication networks from/to remote PLCs. PLCs require programming device which is used to develop and later download the created program into the memory of the controller. Modern PLCs generally contain a real-time operating system, such as OS-9 or VxWorks.

    Programmable logic controllers are intended to be used by engineers without a programming background. For this reason, a graphical programming language called Ladder Diagram (LD, LAD) was first developed. It resembles the schematic diagram of a system built with electromechanical relays and was adopted by many manufacturers and later standardized in the IEC 61131-3 control systems programming standard. As of 2015[update], it is still widely used, thanks to its simplicity. As of 2015[update], the majority of PLC systems adhere to the IEC 61131-3 standard that defines 2 textual programming languages: Structured Text (ST; similar to Pascal) and Instruction List (IL); as well as 3 graphical languages: Ladder Diagram, Function Block Diagram (FBD) and Sequential Function Chart (SFC). Instruction List(IL) was deprecated in the third edition of the standard. Modern PLCs can be programmed in a variety of ways, from the relay-derived ladder logic to programming languages such as specially ada...

    The main difference from most other computing devices is that PLCs are intended-for and therefore tolerant-of more severe conditions (such as dust, moisture, heat, cold), while offering extensive input/output (I/O) to connect the PLC to sensors and actuators. PLC input can include simple digital elements such as limit switches, analog variables from process sensors (such as temperature and pressure), and more complex data such as that from positioning or machine vision systems. PLC output can include elements such as indicator lamps, sirens, electric motors, pneumatic or hydraulic cylinders, magnetic relays, solenoids, or analog outputs. The input/output arrangements may be built into a simple PLC, or the PLC may have external I/O modulesattached to a fieldbus or computer network that plugs into the PLC. The functionality of the PLC has evolved over the years to include sequential relay control, motion control, process control, distributed control systems, and networking. The data h...

    A PLC works in a program scan cycle, where it executes its program repeatedly. The simplest scan cycle consists of 3 steps: 1. read inputs, 2. execute the program, 3. write outputs. The program follows the sequence of instructions. It typically takes a time span of tens of milliseconds for the processor to evaluate all the instructions and update the status of all outputs.If the system contains remote I/O—for example, an external rack with I/O modules—then that introduces additional uncertainty in the response time of the PLC system. As PLCs became more advanced, methods were developed to change the sequence of ladder execution, and subroutines were implemented. This enhanced programming could be used to save scan time for high-speed processes; for example, parts of the program used only for setting up the machine could be segregated from those parts required to operate at higher speed. Newer PLCs now[as of?] have the option to run the logic program synchronously with the IO scannin...

    In his book from 1998, E. A. Parr pointed out that even though most programmable controllers require physical keys and passwords, the lack of strict access control and version control systems, as well as an easy to understand programming language make it likely that unauthorized changes to programs will happen and remain unnoticed. Prior to the discovery of the Stuxnet computer worm in June 2010, security of PLCs received little attention. Modern programmable controllers generally contain a real-time operating systems, which can be vulnerable to exploits in similar way as desktop operating systems, like Microsoft Windows. PLCs can also be attacked by gaining control of a computer they communicate with. Since 2011[update], these concerns have grown as networking is becoming more commonplace in the PLC environment connecting the previously separate plant floor networks and office networks. In February 2021, Rockwell Automation publicly disclosed a critical vulnerability affecting its...

    In recent years "safety" PLCs have become popular, either as standalone models or as functionality and safety-rated hardware added to existing controller architectures (Allen-Bradley Guardlogix, Siemens F-series etc.). These differ from conventional PLC types by being suitable for safety-critical applications for which PLCs have traditionally been supplemented with hard-wired safety relays and areas of the memory dedicated to the safety instructions. The standard of safety level is the SIL. For example, a safety PLC might be used to control access to a robot cell with trapped-key access, or perhaps to manage the shutdown response to an emergency stop on a conveyor production line. Such PLCs typically have a restricted regular instruction set augmented with safety-specific instructions designed to interface with emergency stops, light screens, and so forth. The flexibility that such systems offer has resulted in rapid growth of demand for these controllers.

    PLCs are well adapted to a range of automation tasks. These are typically industrial processes in manufacturing where the cost of developing and maintaining the automation system is high relative to the total cost of the automation, and where changes to the system would be expected during its operational life. PLCs contain input and output devices compatible with industrial pilot devices and controls; little electrical design is required, and the design problem centers on expressing the desired sequence of operations. PLC applications are typically highly customized systems, so the cost of a packaged PLC is low compared to the cost of a specific custom-built controller design. On the other hand, in the case of mass-produced goods, customized control systems are economical. This is due to the lower cost of the components, which can be optimally chosen instead of a "generic" solution, and where the non-recurring engineering charges are spread over thousands or millions of units.[citat...

    Daniel Kandray, Programmable Automation Technologies, Industrial Press, 2010 ISBN 978-0-8311-3346-7, Chapter 8 Introduction to Programmable Logic Controllers
    Walker, Mark John (2012-09-08). The Programmable Logic Controller: its prehistory, emergence and application (PDF) (PhD thesis). Department of Communication and Systems Faculty of Mathematics, Comp...
  2. Simplified Chinese characters - Wikipedia

    en.wikipedia.org/wiki/Zh-cn
    • History
    • Method of Simplification
    • Distribution and Use
    • Education
    • Computer Encoding and Fonts
    • Web Pages
    • Criticism
    • See Also
    • Further Reading
    • External Links

    Singapore and Malaysia

    Singapore underwent three successive rounds of character simplification, eventually arriving at the same set of simplified characters as Mainland China. The first round, consisting of 498 Simplified characters from 502 Traditional characters, was promulgated by the Ministry of Educationin 1969. The second round, consisting of 2287 Simplified characters, was promulgated in 1974. The second set contained 49 differences from the Mainland China system; those were removed in the final round in 197...

    Hong Kong

    A small group called Dou Zi Sei (T:導字社; S:导字社) or Dou Zi Wui (T:導字會; S:导字会) attempted to introduce a special version of simplified characters using romanizations in the 1930s. Today, however, the traditional characters remain dominant in Hong Kong.

    Japan

    After World War II, Japan also simplified a number of Chinese characters (kanji) used in the Japanese language. The new forms are called shinjitai. Compared to Chinese, the Japanese reform was more limited, simplifying only a few hundred characters. Further, the list of simplifications was exhaustive, unlike Chinese simplification – thus analogous simplifications of not explicitly simplified characters (extended shinjitai) are not approved, and instead standard practice is to use the traditio...

    Structural simplification of characters

    1. All characters simplified this way are enumerated in Chart 1 and Chart 2 in Jianhuazi zong biao (简化字总表), "Complete List of Simplified Characters" announced in 1986. 2. Chart 1lists all 350 characters that are used by themselves, and can never serve as 'simplified character components'. 3. Chart 2lists 132 characters that are used by themselves as well as utilized as simplified character components to further derive other simplified characters. Chart 2 also lists 14 'components' or 'radical...

    Derivation based on simplified character components

    1. Chart 3lists 1,753 characters which are simplified based on the same simplification principles used for character components and radicals in Chart 2. This list is non-exhaustive, so if a character is not already found in Chart 1, 2 or 3, but can be simplified in accordance with Chart 2, the character should be simplified.

    Elimination of variants of the same character

    1. Series One Organization List of Variant Characters accounts for some of the orthography difference between Mainland China on the one hand, and Hong Kong and Taiwan on the other. These are not simplifications of character structures, but rather reduction in number of total standard characters. For each set of variant charactersthat share the identical pronunciation and meaning, one character (usually the simplest in form) is elevated to the standard character set, and the rest are obsoleted...

    The People's Republic of China and Singapore generally use simplified characters. They appear very sparingly in printed text produced in Hong Kong, Macau, Taiwan, and overseas Chinese communities, although they are becoming more prevalent as China opens to the world. Conversely, the mainland is seeing an increase in the use of traditional forms, where they are often used on signs, and in logos, blogs, dictionaries, and scholarly works.

    In general, schools in Mainland China, Malaysia and Singapore use simplified characters exclusively, while schools in Hong Kong, Macau, and Taiwan use traditional characters exclusively. Today, simplified Chinese characters predominate among college and university programs teaching Chinese as a foreign language outside of China, such as those in the United States.

    In computer text applications, the GB encoding schememost often renders simplified Chinese characters, while Big5 most often renders traditional characters. Although neither encoding has an explicit connection with a specific character set, the lack of a one-to-one mapping between the simplified and traditional sets established a de facto linkage. Since simplified Chinese conflated many characters into one and since the initial version of the GB encoding scheme, known as GB2312-80, contained only one code point for each character, it is impossible to use GB2312 to map to the bigger set of traditional characters. It is theoretically possible to use Big5 code to map to the smaller set of simplified character glyphs, although there is little market for such a product. Newer and alternative forms of GB have support for traditional characters. In particular, mainland authorities have now established GB 18030 as the official encoding standard for use in all mainland software publications....

    The World Wide Web Consortium's Internationalization working group recommends the use of the language tag zh-Hansas a language attribute value and Content-Language value to specify web-page content in simplified Chinese characters.

    There are ongoing disputes among users of Chinese characters related to the introduction of simplified Chinese characters. Author Liu Shahe was an outspoken critic of the simplification of Chinese characters. He wrote a dedicated column entitled "Simplified Characters are Unreasonable" (简化字不讲理) in the Chinese edition of the Financial Times.

    Bergman, P. M. (1980). The basic English-Chinese, Chinese-English dictionary: using simplified characters (with an appendix containing the original complex characters) transliterated in accordance...
    Bökset, R. (2006). Long story of short forms: the evolution of simplified Chinese characters. Stockholm East Asian monographs, No. 11. Stockholm: Dept. of Oriental Languages, Stockholm University....
    Chen, H. (1987). Simplified Chinese characters. Torrance, CA: Heian. ISBN 0-89346-293-4.
    • Left to Right (Modern usage), Top to Bottom
    • Chinese
  3. microLED - Wikipedia

    en.wikipedia.org/wiki/MicroLED
    • Research
    • Commercialization
    • See Also
    • References
    • External Links

    Inorganic semiconductor microLED (µLED) technology was first invented in 2000 by the research group of Hongxing Jiang and Jingyu Lin of Texas Tech University while they were at Kansas State University. Following their first report of electrical injection microLEDs based on indium gallium nitride (InGaN) semiconductors, several groups have quickly engaged in pursuing this concept. Many related potential applications have been identified. Various on-chip connection schemes of microLED pixel arrays have been employed allowing for the development of single-chip high voltage DC/AC-LEDsto address the compatibility issue between the high voltage electrical infrastructure and low voltage operation nature of LEDs and high brightness self-emissive microdisplays. The microLED array has also been explored as a light source for optogenetics applications and for visible light communications. Early InGaN based microLED arrays and microdisplays were primarily passively driven. The first actively dr...

    microLEDs are considered to have innate potential performance advantages over LCD displays, including higher brightness, lower latency, higher contrast ratio, and greater color saturation, plus intrinsic self-illumination and better efficiency. As of 2016, technological and production barriers have prevented commercialization. As of 2016 a number of different technologies were under active research for the assembling of individual (pixel, or pixel group) LEDs on a substrate. These include chip bonding of microLED chips onto a substrate, considered to have potential for large displays; wafer production methods using etching to produce an LED array followed by bonding to an IC ; and wafer production methods using an intermediate temporary thin film to transfer the LED array to a substrate. Sony launched a 55 inch "Crystal LED Display" in 2012 with 1920x1080 resolution, as a demonstrator product. Sony announced its CLEDIS (Crystal LED Integrated Structure) brand which used surface moun...

    Murphy, David (3 May 2014). "Apple Acquires Micro-LED Display Maker LuxVue Technology". PC Mag.
    Campos, Alvaro (13 May 2014). "Why Did Apple Inc Buy This Micro-LED Tech Startup?". Motley Fool.
  4. Differences between Shinjitai and Simplified characters - Wikipedia

    en.wikipedia.org/wiki/Differences_between_Shinjitai_and...
    • List of Different Simplifications
    • Traditional Characters That May Cause Problems Displaying
    • Different Stroke Orders in Chinese and Japanese

    The old and new forms of the Kyōiku Kanji and their Hànzì equivalents are listed below. In the following lists, the characters are sorted by the radicals of the Japanese kanji. The two Kokuji働 and 畑 in the Kyōiku Kanji List, which have no Chinese equivalents, are not listed here; in Japanese, neither character was affected by the simplifications. Note that 弁 is used to simplify three different Traditional characters (辨, 瓣, and 辯) in Japan. 1. No simplificationin either language (The following characters were simplified neither in Japanese nor in Chinese.) 1. 一 丁 下 三 不 天 五 民 正 平 可 再 百 否 武 夏 中 内 出 本 世 申 由 史 冊 央 向 曲 印 州 表 果 半 必 永 求 九 丸 千 久 少 夫 午 失 末 未 包 年 危 后 兵 我 束 卵 承 垂 刷 重 省 看 勉 七 乳 才 予 事 二 元 亡 六 主 市 交 忘 夜 育 京 卒 商 率 就 人 化 今 仁 付 代 仕 他 令 以 合 全 任 休 件 仲 作 何 位 住 余 低 似 命 使 念 例 供 信 保 便 値 修 借 候 倍 俳 俵 健 停 働 像 先 入 八 分 公 共 弟 並 典 前 益 善 尊 同 周 次 兆 冷 弱 刀 切 別 判 制 券 刻 副 割 力 加 助 努 勇 勤 句 北 疑 十 古 孝 直 南 真 裁 博 上 反 灰 厚 原 台 能 友 収 口 司 右 兄 吸 告 君 味 呼 品 唱 器 四 回 因 困 固 土 去 地 在 寺 均 志 坂 幸 型 城 基 域 喜 境 士 冬 各 夕 外 名 多...

    Some of the traditional Kanji are not included in the Japanese font of Windows XP/2000, and only rectangles are shown. Downloading the Meiryo font from the Microsoft website (VistaFont_JPN.EXE) and installing it will solve this problem. Note that within the Jōyō Kanji there are 62 characters the old forms of which may cause problems displaying: Kyōiku Kanji (26): Grade 2 (2 Kanji): 海 社 Grade 3 (8 Kanji): 勉 暑 漢 神 福 練 者 都 Grade 4 (6 Kanji): 器 殺 祝 節 梅 類 Grade 5 (1 Kanji): 祖 Grade 6 (9 Kanji): 勤 穀 視 署 層 著 諸 難 朗 Secondary-School Kanji (36): 欄 廊 虜 隆 塚 祥 侮 僧 免 卑 喝 嘆 塀 墨 悔 慨 憎 懲 敏 既 煮 碑 祉 祈 禍 突 繁 臭 褐 謁 謹 賓 贈 逸 響 頻 These characters are Unicode CJK Unified Ideographs for which the old form (kyūjitai) and the new form (shinjitai) have been unified under the Unicode standard. Although the old and new forms are distinguished under the JIS X 0213 standard, the old forms map to Unicode CJK Compatibility Ideographs which are considered by Unicode to be canonically equivalent to the new forms and ma...

    Some characters, whether simplified or not, look the same in Chinese and Japanese, but have different stroke orders. For example, in Japan, 必 is written with the top dot first, while the Traditional stroke order writes the 丿 first. In the characters 王 and 玉, the vertical stroke is the third stroke in Chinese, but the second stroke in Japanese.Taiwan and Hong Kong use Traditional characters, though with an altered stroke order.

  5. Starbucks - Wikipedia

    en.wikipedia.org/wiki/Starbucks

    Starbucks' caffe lattes. Starbucks Corporation is an American multinational chain of coffeehouses and roastery reserves headquartered in Seattle, Washington. As the world's largest coffeehouse chain, Starbucks is seen to be the main ...

  6. Tōyō kanji - Wikipedia

    en.wikipedia.org/wiki/Tōyō_kanji
    • Reform
    • Applications and Limitations
    • Mazegaki
    • List of The 1,850 Tōyō Kanji
    • See Also
    • External Links

    Thousands of kanji characters were in use in various writing systems, leading to great difficulties for those learning written Japanese. Additionally, several characters had identical meanings but were written differently from each other, further increasing complexity. After World War II, the Ministry of Education decided to minimize the number of kanji by choosing the most commonly used kanji, along with simplified kanji (see Shinjitai) commonly appearing in contemporary literature, to form the tōyō kanji. This was an integral part of the postwar reform of Japanese national writing. This was meant as a preparation for re-introducing their previous unsuccessful reform abolishing Chinese characters. Although the postwar timing meant no public debate was held on the future of the Japanese written language, the defenders of the original kanji system considered and accepted the tōyō kanji as a reasonable compromise. Since this compromise could not then be withdrawn in favour of more rad...

    In addition to a list of the standardized tōyō kanji, the reform published by the Ministry for Education in 1946 also contains a set of guidelines for their use. Regarding provenance and scope, the foreword of the document states that: 1. The table of tōyō kanji put forth therein, are the selection of kanji recommended for use by the general public, including legal and governmental documents, newspapers, and magazines. 2. The presented kanji are selected as an approximate set of those characters found to be of no insignificant utility in the lives of today's Japanese citizens. 3. Concerning proper nouns, there is a wide range of usage beyond what may be formulated as rules, and consequently they are treated as outside the scope of this standard. 4. The simplified character forms from modern custom are taken as the proper form, and their original forms are provided alongside them for reference. 5. A systemization of the character forms and their readings is still under consideration...

    Because the majority of character-based words are composed of two (or more) kanji, many words were left with one character included in the Tōyō kanji, and the other character missing. In this case, the recommendation was to write the included part in kanji and the excluded part in kana, e.g. ふ頭 for 埠頭 and 危ぐ for 危惧. These words were called mazegaki(交ぜ書き, "mixed characters").

    Bold in 1981 and 2010 year added kanji 一 丁 七 丈 三 上 下 不 且 世 丘 丙 中 丸 丹 主 久 乏 乗 乙 九 乳 乾 乱 了 事 二 互 五 井 亜 亡 交 享 京 人 仁 今 介 仕 他 付 代 令 以 仰 仲 件 任 企 伏 伐 休 伯 伴 伸 伺 似 但 位 低 住 佐 何 仏 作 佳 使 来 例 侍 供 依 侮 侯 侵 便 係 促 俊 俗 保 信 修 俳 俵 併 倉 個 倍 倒 候 借 倣 値 倫 仮 偉 偏 停 健 側 偶 傍 傑 備 催 伝 債 傷 傾 働 像 僚 偽 僧 価 儀 億 倹 儒 償 優 元 兄 充 兆 先 光 克 免 児 入 内 全 両 八 公 六 共 兵 具 典 兼 冊 再 冒 冗 冠 冬 冷 准 凍 凝 凡 凶 出 刀 刃 分 切 刈 刊 刑 列 初 判 別 利 到 制 刷 券 刺 刻 則 削 前 剖 剛 剰 副 割 創 劇 剤 剣 力 功 加 劣 助 努 効 劾 勅 勇 勉 動 勘 務 勝 労 募 勢 勤 勲 励 勧 勺 匁 包 化 北 匠 匹 匿 区 十 千 升 午 半 卑 卒 卓 協 南 博 占 印 危 却 卵 巻 卸 即 厘 厚 原 去 参 又 及 友 反 叔 取 受 口 古 句 叫 召 可 史 右 司 各 合 吉 同 名 后 吏 吐 向 君 吟 否 含 呈 呉 吸 吹 告 周 味 呼 命 和 咲 哀 品 員 哲 唆 唐 唯 唱 商 問 啓 善 喚 喜 喪 喫 単 嗣 嘆 器 噴 嚇 厳 嘱 囚 四 回 因 困 固 圏 国 囲 園 円 図 団 土 在 地 坂 均 坊 坑 坪 垂 型 埋 城 域 執 培 基 堂 堅 堤 堪 報 場 塊 塑 塔 塗 境 墓 墜 増 墨 堕 墳 墾 壁 壇 圧 塁 壊 士 壮 壱 寿 夏 夕 外 多 夜 夢 大 天 太 夫 央 失 奇 奉 奏 契 奔 奥 奪 奨 奮 女 奴 好 如 妃 妊 妙 妥 妨 妹 妻 姉 始 姓 委 姫 姻 姿 威 娘 娯 娠 婆 婚 婦 婿 媒 嫁 嫡 嬢 子 孔 字 存 孝 季 孤 孫 学 宅 宇 守 安 完 宗 官 宙 定 宜 客 宣 室 宮 宰 害 宴 家 容 宿 寂 寄 密 富 寒 察 寡 寝 実 寧 審 写 寛 寮 宝 寸 寺 封 射 将 専 尉 尊 尋 対 導 小 少 就 尺 尼 尾 尿 局 居 届 屈...

  7. Kyōiku kanji - Wikipedia

    en.wikipedia.org/wiki/Kyoiku_kanji

    Kyōiku kanji (教育漢字, literally "education kanji"), also known as Gakunenbetsu kanji haitōhyō (学年別漢字配当表, literally "list of kanji by school year") is a list of 1,026 kanji and associated readings developed and ...

  8. List of kanji by stroke count - Wikipedia

    en.wikipedia.org/wiki/List_of_kanji_by_stroke_count

    This Kanji index method groups together the kanji that are written with the same number of strokes. Currently, there are 2,187 individual kanji listed. Characters followed by an alternate in (parentheses) indicate a difference between the ...

  9. List of jōyō kanji - Wikipedia

    en.wikipedia.org/wiki/Joyo_kanji_list

    List of characters For brevity, only one English translation is given per kanji. The "Grade" column specifies the grade in which the kanji is taught in Elementary schools in Japan.Grade "S" means that it is taught in ...

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