PROGRAMMABLE LOGIC CONTROLLERS

时间:2012-03-26 15:24:38
【文件属性】:

文件名称:PROGRAMMABLE LOGIC CONTROLLERS

文件大小:323KB

文件格式:DOC

更新时间:2012-03-26 15:24:38

PROGRAMMABLE LOGIC CONTROLLERS

Control engineering has evolved over time. In the past humans were the main method for controlling a system. More recently electricity has been used for control and early electrical control was based on relays. These relays allow power to be switched on and off without a mechanical switch. It is common to use relays to make simple logical control decisions. The development of low cost computer has brought the most recent revolution, the Programmable Logic Controller (PLC). The advent of the PLC began in the 1970s, and has become the most common choice for manufacturing controls.


网友评论

  • 内容较少,只有12页。