【正文】 eciding how and when the data should be processed. The control unit directs the operation of the arithmeticlogic ，控制器控制運(yùn)算器的操作。 The more familiar decimal number system and a whole host of software languages can utilize the binary system to permit munication between puters and human 用二進(jìn)制計(jì)數(shù)法在電腦和人之間實(shí)現(xiàn)交流。 s memory can be easily changed, and therefore different programs can be placed into memory, the digital puter can be used for a wide variety of 容你能夠很容易被改變，并且不同的程序都能夠被存入，所以數(shù)字電腦能夠用于多種應(yīng)用。 . The software consists of the programs and instructions stored in memory and in external storage units. It is the software that assigns the various functions which the user desires the system to acplish to the puter. 軟件由程序和存儲(chǔ)在內(nèi)存與外存中的指令組成。 It adds, subtracts, multiplies, divides, and pares numbers according to programmed instructions. The memory of the puter is the storage unit. 它根據(jù)編制的程序完成數(shù)的加、減、乘、除和比較。 一般用途的數(shù)字計(jì)算機(jī)由三種基本硬件組成 .Central processing unit (CPU) 微處理器 .Memory 存儲(chǔ)器 .Input/output ( I/0 )section 輸入 /輸出設(shè)備 The relationship of these three ponents is illustrated in Fig. . The central processing unit is often considered to consist of two subsections。 a control unit and an arithmeticlogic unit (ALU). 這三個(gè)組成部分的關(guān)系如圖 所示，中央處理器通常被認(rèn)為包含兩部分 :一個(gè)控制器和一個(gè)運(yùn)算器 .The control unit coordinates the operations of all the other ponents. 控制器控制所有其他組成部分的運(yùn)輸。存儲(chǔ)器完成電腦的記憶功能。軟件將使用者所要求系統(tǒng)完成的各項(xiàng)功能分配給計(jì)算機(jī)。 Regardless of the application, the puter executes the program through its ability to manipulate data and numbers in their most elementary form. 不考慮這些應(yīng)用，電腦能自動(dòng)執(zhí)行程序并以最基本的形式完成數(shù)字和數(shù)據(jù)的運(yùn)算。 Central Processing Unit (CPU) 中央處理器 The central processing unit (CPU) regulates the operation of all system ponents and performs the arithmetic and logical operations on the data. 中央處理器控制所有系統(tǒng)組成的操作并進(jìn)行數(shù)據(jù)的算術(shù)和邏輯運(yùn)算。 It sends data to the ALU and tells the ALU what functions to perform on the data and where to store the results. 它將數(shù)據(jù)發(fā)送給運(yùn)算器并告知運(yùn)算器數(shù)據(jù)所要求的處理操作和結(jié)果的存儲(chǔ)位置。 The logic section can also be used to alter the sequence in which instructions are executed when certain conditions are indicated and to perform other functions, such as editing and masking data for arithmetic operations. 當(dāng)指出某些條件時(shí)邏輯器能夠改變程序執(zhí)行的順序，也能夠完成其他功能，例如為運(yùn)算操作編輯和屏蔽數(shù)據(jù)。 The number of bits in the register establishes the word length with which the puter is capable of handling. The number of bits per word can be as few as 4 ( early microputers ) or as many as 64 ( large scientific puters ). Computer Programming Languages 存儲(chǔ)器的位數(shù)代表了電腦能夠處理的字長(zhǎng)，每個(gè)字所占位數(shù)最少到 4 個(gè)（早期微型計(jì)算機(jī)）最多到 64 個(gè)（大型科學(xué)計(jì)算機(jī)） The binary number system could be used to represent any decimal number, alphabetic letter, or other mon symbol. 二進(jìn)制數(shù)能夠用來(lái)表示十進(jìn)制數(shù)、字母，或者其他一般符號(hào)。 Also, different machines use different machine languages. 同時(shí)，不同的機(jī)器使用不同的機(jī)器語(yǔ)言。 In a data processing system, this munication is acplished by various input/output devices such as card readers， printers， and CRT consoles. 在數(shù)據(jù)處理系統(tǒng)中，這種交流是通過(guò)輸入 /輸出設(shè)備例如讀卡器、打印機(jī)、 CRT 控制板等完成的。 In the following sections we examine some of the important ponents of a puter process control system. 下面的部分我們檢查計(jì)算機(jī)過(guò)程控制系統(tǒng)的一些重要部分制造過(guò)程數(shù)據(jù)。 For monitoring the process，input data must be entered into the puter. 。他們是： .Analog to digital A/D .Contact input 觸點(diǎn)輸入 .Pulse counters 脈沖計(jì)數(shù)器 .Digital to analog D/A .Contact output 觸點(diǎn)輸出 .Pulse generators 觸點(diǎn)輸出 Computer Network Structures 計(jì)算機(jī)網(wǎng)絡(luò)結(jié)構(gòu) Network introduction 網(wǎng)絡(luò)介紹 The term “ puter work refers to the actual physical connections between puters in different areas. 計(jì)算機(jī)網(wǎng)絡(luò)這個(gè)術(shù)語(yǔ)是指計(jì)算機(jī)和不同的區(qū)域之間的物理連接。 Computer work can be used in almost every case. 計(jì)算機(jī)網(wǎng)絡(luò)幾乎可用于任何事。編程還可以手動(dòng)或者在計(jì)算機(jī)輔助下來(lái)完成。行動(dòng)指令涉及插值的類(lèi)型以及刀具或者工作臺(tái)的緩慢和快速移動(dòng)。那么一個(gè)包括執(zhí)行特定操作所需必要信息的程序表就準(zhǔn)備好了，例如刀具切削，主軸轉(zhuǎn)速，進(jìn)給，切削深度，切削液，以及刀具或者工件間的相對(duì)位置或者移動(dòng)。 Manual programming can be done by someone who is knowledgeable about the particular manufacturing process and is able to understand, read, and change part programs. Because they are familiar with machine tools and process capabilities, skilled machinists can do manual programming with some training in programming. However, the work involved is tedious, timeconsuming, and uneconomical consequently, manual programming is used mostly in simple pointtopoint applications. 手工編程可以由那些具有特定制造工藝知識(shí)和能夠理解，閱讀以及更改部分程序的人來(lái)完成。 (2) Computeraided programming. Computeraided part programming involves special symbolic programming languages that determine the coordinate points of corners, edges, and surfaces of the part. Programming language is the means of municating with the puter and involves the use of symbolic Characters. The programmer describes the ponent to be processed in this language, and the puter converts it to mands for the NC machine. Several languages having various features and applications are mercially available. The first language that used Englishlike statements was developed in the late 1950s and is called APT (for Automatically Programmed Tools). This language, in its various expanded forms, is still the most widely used for both pointtopoint and continuouspath programming.（ 2） 計(jì)算機(jī)輔助編程。許多種商業(yè)應(yīng)用上的語(yǔ)言有多種多樣的特點(diǎn)和應(yīng)用。刀具的路徑是在類(lèi)似于一個(gè) CAD程序的大量的繪圖環(huán)境下制造出來(lái)的。 ● Relatively easy use of symbolic language. ● Reduced programming time. Programming is capable of acmodating a large amount of data concerning machine characteristics and process variables, such as power, speeds, feed, tool shape, pensation for tool shape changes, tool wear, deflections, and coolant use. ● Reduced possibility of human error which can occur in manual programming. ● Capability of simple changeover of machining sequence or from machine to machine. ● Lower cost because less time is required for programming. 比較容易使用的 符號(hào)語(yǔ)言 縮短了編程時(shí)間。 The use of programming languages not only results in higher part quality but also allows for more rapid development of machining instructions. In addition, s