外文翻譯--可設(shè)計(jì)的邏輯控制器-免費(fèi)閱讀
【正文】 這一階段的小型產(chǎn)品向超小型化和加強(qiáng)型功能發(fā)展，有 16點(diǎn) I/O， 24點(diǎn) I/O的整體型小型 PLC在小型 PLC上配置模擬量 I/O、通信口、高速計(jì)數(shù)，指令上也設(shè)置有算術(shù)運(yùn)算、比較指令以及 PID調(diào)節(jié)指令。 第二階段： PLC 的容量有所擴(kuò)展， I/O點(diǎn)數(shù)從 512點(diǎn)至 1024點(diǎn)，用戶程序存儲(chǔ)區(qū)擴(kuò)展到8KB以上，速度也有提高，掃描速度達(dá)到 5~6ms/KB，指令功能除了基本的邏輯運(yùn)算、計(jì)時(shí)、計(jì)數(shù)外，還增加了算術(shù)運(yùn)算指令、比較指令，以及模擬量處理指令等，輸入／輸出類型也由純開關(guān)量 I/O，擴(kuò)展為帶模擬量的 I/O。 自 1976年以來，微處理器開始引入 PLC領(lǐng)域，大大加強(qiáng) 了 PLC的作用，使 PLC由簡(jiǎn)單地代替繼電器電路，而發(fā)展為先 進(jìn)的控制裝置。 PLC技術(shù)代表了當(dāng)今電氣程序控制的最先進(jìn)水平。 在 IEC 611313 標(biāo)準(zhǔn)之下， PLCs 能是規(guī)劃使用以標(biāo)準(zhǔn)為基礎(chǔ)的規(guī)畫語言?？稍O(shè)計(jì)的控制器最初是被收養(yǎng)的被汽車制造工業(yè) , 哪里軟件代替的校訂那再配線難 以線加強(qiáng)的控制嵌板當(dāng)生產(chǎn)模型改變。 特征 主要的不同從其他的計(jì)算機(jī)是 PLC 對(duì)嚴(yán)格的情況 (灰塵 , 濕氣 , 熱 , 寒冷 , 及其他 ) 是披甲的和有設(shè)備為廣泛的輸入 /輸出 (輸入／輸出 ) 安排。t replace control hardware. Since 1976, the microprocessor starts lead into the PLC realm, consumedly strengthen a PLC function and make PLC from in brief replace after the electric appliances electric circuit, but develop to equip into the control which enters first. The PLC has to collect and handles a great deal of data, pletion mathematics operation and correspond by letter with other intelligence spare parts nowadays of ability, and have the forerunner39。s in last century, although the small scaled calculator has been gradually perfect and apply realm is also continuously extending, the small scaled calculator used for switch control system, obviously exist the circumstance of Malaysia pull a small car again, this is because the characteristics of small scaled calculator decide: The plait distance woven distance plications, requested to have higher level personnel and operate a personnel。Programmable logic controller A programmable logic controller (PLC) or programmable controller is a digital puter used for automation of industrial processes, such as control of machinery on factory assembly lines. Unlike generalpurpose puters, the PLC is designed for multiple inputs and output arrangements, extended temperature ranges, immunity to electrical noise, and resistance to vibration and impact. Programs to control machine operation are typically stored in batterybacked or nonvolatile memory. A PLC is an example of a real time system since output results must be produced in response to input conditions within a bounded time, otherwise unintended operation will result. PLC and Programmable Logic Controller are registered trademarks of the AllenBradley Company, although they are widely used generically. Features The main difference from other puters is that PLC are armored for severe condition (dust, moisture, heat, cold, etc) and have the facility for extensive input/output (I/O) arrangements. These connect the PLC to sensors and actuators. PLC read limit switches, analog process variables (such as temperature and pressure), and the positions of plex positioning systems. Some even use machine vision. On the actuator side, P L C operates electric motors, pneumatic or hydraulic cylinders, magic relays or solenoids, or analog outputs. The input/output arrangements may be built into a simple PLC, or the PLC may have external I/O modules attached to a puter work that plugs into the PLC. P L C was invented as replacements for automated systems that would use hundreds or thousands of relays, cam timers, and drum sequencers. Often, a single PLC can be programmed to replace thousands of relays. Programmable controllers were initially adopted by the automotive manufacturing industry, where software revision replaced the rewiring of hardwired control panels when production models changed. Many of the earliest PLC express
畢業(yè)設(shè)計(jì)相關(guān)推薦
鄂ICP備17016276號(hào)-1