可編程邏輯控制器plc外文翻譯-plc設(shè)計(jì)-wenkub.com
2025-05-07 15:03 本頁(yè)面
【正文】 然而，如果必須根據(jù)目標(biāo)函數(shù)的測(cè)量值來(lái)調(diào)整參數(shù)，則要利用反饋回路實(shí)現(xiàn)適應(yīng)性控制。為這種指標(biāo)而設(shè)計(jì)的控制系統(tǒng)就是靜態(tài)適應(yīng)性系統(tǒng)。一個(gè)給定過(guò)程的目標(biāo)函數(shù)可能是被調(diào)量的衰減度。為被調(diào)量規(guī)定一個(gè)數(shù)值（即設(shè)定值）是不夠的，因?yàn)橐獫M足這一指標(biāo)。在這里提到的設(shè)備代表了與 I/O 連接的各種傳感器和調(diào)節(jié)器，它門(mén)是系統(tǒng)的手臂、腿、眼睛和耳朵，其中包括按鈕、限制開(kāi)關(guān)、行程開(kāi)關(guān)、光敏元件、熱電偶、位置傳感器，作為輸入的讀卡機(jī)、標(biāo) 燈、顯示設(shè)備、發(fā)動(dòng)機(jī)、 DC 和 AD 驅(qū)動(dòng)器、螺線管和作為輸出的打印機(jī)。接著是 I/O 模塊，它的功能是為 CPU 提供控制水平信號(hào)，并把他們轉(zhuǎn)化為適合連接工廠級(jí)別的傳感器和調(diào)節(jié)器的標(biāo)準(zhǔn)電壓和電流。只有當(dāng)涉及到附加的、更改的或重新定位的輸入 /輸出裝置時(shí)，才需要個(gè)性硬件。例如，處理可被編程為根據(jù)鍋爐實(shí)際溫度（模擬輸出）。 諸如電磁線圈或電動(dòng)起動(dòng)機(jī)之類(lèi)的輸出裝置被連接到輸出模塊的 接線上，并從處理器接受它的位移信號(hào)。處理器監(jiān)測(cè) I/O 的狀態(tài)，然后依據(jù)儲(chǔ)存在 PLC 存儲(chǔ)器中指令更新輸出。這個(gè)新系統(tǒng)被稱作 “可編程控制器 ”。其他輸出裝置包括模擬裝置、數(shù)字 BCD 顯示、 ASCII 兼容裝置、伺服變 速驅(qū)動(dòng)器、甚至計(jì)算機(jī)。 PLC 通過(guò)輸入 /輸出 (I/O)裝置發(fā)出控制信號(hào)和接受輸入信號(hào)。 1 Programmable Logic Controllers Programmable logic controller (plc) is a solidstate device used to control machine motion or process operation by means of a stored program. The PLC sends output control signals and receives input signals through input/output (I/O) devices. A PLC controls outputs in response to stimuli at the inputs according to the logic prescribed by the stored program. The inputs are made up of limit switches, pushbuttons, thunbwheels. Switches, pulses, analog signals, ASCLL serial data, and binary or BCD data from absolute position encoders. The outputs are voltage or current levels to drive end devices such as solenoids, motor starters, relays, lights, and so on. Other output devices include analog devices, digital BCD displays, ASCII patible devices, servo variablespeed drives, and even puters. Programmable controllers were developed (circa in 1968) when General Motors Corp, and other automobile manufacturers were experimenting to see if there might be an alternative to scrapping all their hardwired control panels of machine tools and other production equipment during a model changeover. This annual tradition was necessary because rewiring of the panels wa
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