外文翻譯--plc控制系統(tǒng)設(shè)計(jì)的要點(diǎn)-plc設(shè)計(jì)-全文預(yù)覽
【正文】 昂貴，并且該方式不易于現(xiàn)場(chǎng)調(diào)試。不同公司的產(chǎn)品，對(duì)系統(tǒng)總點(diǎn)數(shù)及擴(kuò)展模塊的數(shù)量都有限制，當(dāng)擴(kuò)展仍不能滿足要求時(shí)，可采用網(wǎng)絡(luò)結(jié)構(gòu)；同時(shí)，有些廠家產(chǎn)品的個(gè)別指令不支持?jǐn)U展模塊，因此，在進(jìn)行軟件編制時(shí)要注意。 當(dāng)用 PLC 進(jìn)行網(wǎng)絡(luò)設(shè)計(jì)時(shí)，其難度比 PLC 單機(jī)控制大得多。 最后，還要向 PLC 的商家尋求網(wǎng)絡(luò)設(shè)計(jì)和軟件技術(shù)支持及詳細(xì)的技術(shù)資料，至于選用幾層工作站，依你的系統(tǒng)大小而定。 。若用圖形編程器或軟件包編程，則可直接編程，若用手持編程器編程，應(yīng)先畫出梯形圖，然后編程，這樣可少出錯(cuò)，速度也快。否則，不能適應(yīng)你的實(shí)時(shí)要求，造成系統(tǒng)崩潰。各公司的擴(kuò)展模塊種類很多，如單輸入模塊、單輸出模塊、輸入輸出模塊、溫度模塊、高速輸入模塊等。 ⑤ 盡量選用大公司的產(chǎn)品其質(zhì)量有保障，且技術(shù)支持好，一般售后服務(wù)也較好，還有利于你的產(chǎn)品擴(kuò)展與軟件升級(jí)。這種方式效率低，但對(duì)于系統(tǒng)容量小，用量小的產(chǎn)品比較適宜，并且體積小，易于現(xiàn)場(chǎng)調(diào)試，造價(jià)也較低。目前還未發(fā)現(xiàn)各公司之間完全兼容的產(chǎn)品。數(shù)，并且在選購(gòu) PLC 時(shí)要在實(shí)際需要點(diǎn)數(shù)的基礎(chǔ)上留有一定余量（ 10%）。 在現(xiàn)代化的工業(yè)生產(chǎn)設(shè)備中，有大量的數(shù)字量及模擬量的控制裝置，例如電機(jī)的起停，電磁閥的開閉，產(chǎn)品的計(jì)數(shù)，溫度、 壓力、流量的設(shè)定與控制等，工業(yè)現(xiàn)場(chǎng)中的這些自動(dòng)控制問題，若采用 可編程序控制器（ PLC）來解決自動(dòng)控制問題已成為最有效的工具之一，本文敘述 PLC 控制系統(tǒng)設(shè)計(jì)時(shí)應(yīng)該注意的問題。 PLC 程序的操作速度是非?？斓?.PLC 邏輯運(yùn)行的速度由掃描時(shí)間決定 , 它按毫秒計(jì)算。 先進(jìn)的 PLC 系統(tǒng) , 對(duì)于每個(gè)可能的故障都能描述其操作信息。 ⑥可觀察性 . 在 CRT熒屏上可以直接看到 PLC的電路運(yùn)行。 ⑤容易調(diào)試。 的確 , 從一個(gè)繼電器上可獲得一百個(gè)觸點(diǎn) 如果計(jì)算機(jī)有足夠大的內(nèi)存。 ③大量的接觸器。 ②實(shí)現(xiàn)變化和改正錯(cuò)誤。 以下是使用一個(gè)可編程控制器的 8 個(gè)主要優(yōu)點(diǎn)。 因?yàn)椴皇煜ぬ輬D表或數(shù)字原則的人， 卻要花較多的時(shí)間去學(xué)習(xí)。 PLCs 也廣泛地被用于建立能源和安全控制制系統(tǒng)。 在 1980 年代中，隨著計(jì)算機(jī)價(jià)位的變化 , PLC 的使用指數(shù)逐漸增加。 編程是復(fù)雜的而且需要一個(gè)高度訓(xùn)練的程序師來修改。 早的 PLCs 連同其他的新自動(dòng)化技術(shù)的使用縮短了轉(zhuǎn)換時(shí)間。 一些能裝在你的襯衫口袋，沒有一副卡片大并且能在任何時(shí)間寫作 , 引入的 PLC 將會(huì)包括現(xiàn)在微模型的許多特征 ,它只有 TicTac 的糖果盒子的大小。 它也能操作任何輸出為變量 (模擬 ) 的系統(tǒng) . PLC 能通過開關(guān)裝置 (不連續(xù)的 , 或數(shù)字的 ) 或輸入變量 (模擬 ) 的裝置在輸入端進(jìn)行操作。在操作計(jì)算機(jī)方面不熟練的人能對(duì)它進(jìn)行規(guī)劃，控制 , 而且操作。s Plc development software packages expensive, and that means not at the scene debugging. Therefore, the system should be based on the size and level of difficulty, the length of the development cycle and reasonable funding of the purchase Plc products. Fifth, And large panies to choose their quality guaranteed products, and good technical support, after sales services are generally better, but also help expand your product and software upgrades. For small systems, such as 80 points within the system. Generally do not need expansion。Plc control system design elements Originally, the PLC was represented by the acronym PC. There was some confusion with using this acronym as it is monly accepted to represent personal puter. Therefore, PLC is now monly accepted to mean programmable logic contoller. A PLC is a userfriendly, microprocessorbased specialized puter that carries out control functions of many types and leves of plexity. Its purpose is to monitor crucial process parameters and adjust process operations accordingly. It can be programmed, controlled, and operated by a person unskilled in operating puter. Essentially, a PLC’s operator draws the lines and devices of ladder diagrams with a keyboard onto a display screen. The resulting drawing is converted into puter machine language and run as a user program. The puter takes the place of much of the external wiring required for control of a process. The PLC will operate any system that has output devices that go on and off (known as discrete, or digital, outputs). It can also operate any system with variable (analog) outputs. The PLC can be operated on the input side by onoff devices (discrete, or digital) or by variable (analog) input devices. Today, the big unit growth in the PLC industy is at the low endwhere small keeps getting smaller. When a few years ago the micro PLC entered the market, some thougt that these devices had “bottomed out”. Now,nano PLCsgenerally defined as those with 16 or fewer I/Oare spreading. Some can fit into your shirt pocket, being no larger than a deck of cards and at the time of this wri
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