【正文】 e controllers that e out in the process control system business will embrace a lot of more PLC technology and a lot more PLC functionality than they ever did before.Communications and MAPCommunications are vital to an individual automation cell and to be automated factory as a whole. We39。 Programmable controls are being used for more and more sophisticated operations, languages other than ladder logic bee more practical, efficient, and powerful. For example, it39。外文資料翻譯The singlechip microputer is the culmination of both the development of the digital puter and the integrated circuit arguably the two most significant inventions of the 20th century.Some employ the split program/data memory of the Harvard architecture, shown in , others follow the philosophy, widely adapted for generalpurpose puters and microprocessors, of making no logical distinction between program and data memory as in the Princeton architecture, shown in . In general terms a singlechip microputer is characterized by the incorporation of all the units of a puter into a single device, as shown in Fig35A3. These two types of architecture are found in singlechip microputer. Fig. A1 A Harvard type Fig. A2 A conventional Princeton puterRead only memory (ROM)ROM is usually for the permanent, nonvolatile storage of an applications program .Many microputers and microcontrollers are intended for highvolume applications and hence the economical manufacture of the devices requires that the contents of the program memory be mitted permanently during the manufacture of chips. Clearly, this implies a rigorous approach to ROM code development since changes cannot be made after manufacture .This development process may involve emulation using a sophisticated development system with a hardware emulation capability as well as the use of powerful software tools.Some manufacturers provide additional ROM options by including in their range devices with (or intended for use with) user programmable memory. The simplest of these is usually device which can operate in a microprocessor mode by using some of the input/output lines as an address and data bus for accessing external memory. This type of device can behave functionally as the single chip microputer from which it is derived albeit with restricted I/O and a modified external circuit. The use of these ROM less devices is mon even in production circuits where the volume does not justify the development costs of custom onchip ROM。Automation .inc。s being automated doesn39。s unlikely that an individual PLC would talk to broad MAP anyway, makers are concentrating on proprietary networks. According to Sal Provanzano, users fear that if they do get on board and vendors withdraw from MAP, they39。許多微機和單片機用于大批量的應(yīng)用，因此，要經(jīng)濟(jì)的制造設(shè)備就要在制造期間的把程序存儲器中的內(nèi)容永久性的刻錄在芯片中。他們提供的單芯片器件對于容量要求低的優(yōu)勢，這些基于EPROM的設(shè)備也非常有吸引力，在以下方面的板載I/O等，方便用戶靈活編程。因而， CPU非常普遍的被用來很好的處理這種類型的數(shù)據(jù)。這個設(shè)施可能用作一個產(chǎn)品系列的延伸，因為連續(xù)放大器對片上存儲器可能太大，這建立在現(xiàn)有的軟件基礎(chǔ)上是不合適的。這可以由每個程序中的執(zhí)行時間分支認(rèn)真評估，但除最簡單的程序外，他的工作效率不高。定時元件大多數(shù)微型計算機時鐘電路只需要簡單的計時元件。而且有越來越多像C和BASIC語言的興趣。第二種是你必須融入順序邏輯。然而。然而，誰是那些感覺的I/O最終將成為更具有普遍性?！叭绻覀冮_始銷售該產(chǎn)品的實物，那我們還有什么可生產(chǎn)的？”Jannotta說道隨著更多智能I/O出現(xiàn)，薩爾Provanzano認(rèn)為在不同的制造商中間這將導(dǎo)致更多