描述
可編程控制器是60年代末在美國(guó)首先出現(xiàn),當(dāng)時(shí)叫可編程邏輯控制器PLC(Programmable Logic Controller),目的是用來(lái)取代繼電器,以執(zhí)行邏輯判斷、計(jì)時(shí)、計(jì)數(shù)等順序控制功能。PLC的基本設(shè)計(jì)思想是把計(jì)算機(jī)功能完善、靈活、通用等優(yōu)點(diǎn)和繼電器控制系統(tǒng)的簡(jiǎn)單易懂、操作方便、價(jià)格便宜等優(yōu)點(diǎn)結(jié)合起來(lái),控制器的硬件是標(biāo)準(zhǔn)的、通用的。根據(jù)實(shí)際應(yīng)用對(duì)象,將控制內(nèi)容編成軟件寫(xiě)入控制器的用戶程序存儲(chǔ)器內(nèi)??刂破骱捅豢貙?duì)象連接方便。
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