杨光光 pc外文文献译文.doc

  1. 1、本文档共16页,可阅读全部内容。
  2. 2、有哪些信誉好的足球投注网站(book118)网站文档一经付费(服务费),不意味着购买了该文档的版权,仅供个人/单位学习、研究之用,不得用于商业用途,未经授权,严禁复制、发行、汇编、翻译或者网络传播等,侵权必究。
  3. 3、本站所有内容均由合作方或网友上传,本站不对文档的完整性、权威性及其观点立场正确性做任何保证或承诺!文档内容仅供研究参考,付费前请自行鉴别。如您付费,意味着您自己接受本站规则且自行承担风险,本站不退款、不进行额外附加服务;查看《如何避免下载的几个坑》。如果您已付费下载过本站文档,您可以点击 这里二次下载
  4. 4、如文档侵犯商业秘密、侵犯著作权、侵犯人身权等,请点击“版权申诉”(推荐),也可以打举报电话:400-050-0827(电话支持时间:9:00-18:30)。
查看更多
杨光光 pc外文文献译文

外文文献译文 设计(论文)题目: 可编程逻辑控制器 专业与班级: 学生姓名: 指导教师: 2010年3月18日 Programmable logic controller A programmable logic controller (PLC) or programmable controller is a HYPERLINK /wiki/Digital_computerdigital computer used for HYPERLINK /wiki/Automationautomation of HYPERLINK /wiki/Electromechanicalelectromechanical processes, such as control of machinery on factory HYPERLINK /wiki/Assembly_lineassembly lines, amusement rides, or lighting fixtures. PLCs are used in many industries and machines. Unlike general-purpose computers, 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 battery-backed or HYPERLINK /wiki/Non-volatile_memorynon-volatile memory. A PLC is an example of a HYPERLINK /wiki/Real-time_computingreal time system since output results must be produced in response to input conditions within a bounded time, otherwise unintended operation will result. 1.History The PLC was invented in response to the needs of the American automotive manufacturing industry. Programmable logic controllers were initially adopted by the automotive industry where software revision replaced the re-wiring of hard-wired control panels when production models changed. Before the PLC, control, sequencing, and safety interlock logic for manufacturing automobiles was accomplished using hundreds or thousands of HYPERLINK /wiki/Relayrelays, HYPERLINK /wiki/Cam_timercam timers, and HYPERLINK /wiki/Drum_sequencerdrum sequencers and dedicated closed-loop controllers. The process for updating such facilities for the yearly model HYPERLINK /wiki/Changeoverchange-over was very time consuming and expensive, as HYPERLINK /wiki/Electricianelectricians needed to individually rewire each and every relay. In 196

文档评论(0)

seunk + 关注
实名认证
内容提供者

该用户很懒,什么也没介绍

1亿VIP精品文档

相关文档