【正文】 tool39。 decode the machining instructions in part codes and do decimal173。codes and M173。Sky (ShenYang Institute of Computing Technology) 《 NC Technology 》 E－ mail: .CNC SOFTWARE In CNC system, there are various kinds of software codes, which fall into two groups: user software and system software.《 NC Technology 》 E－ mail: .User software216。 HNC (HuaZhong Numerical Control system216。BRANDLEY (American A173。FANUC (Japan)216。 CNC unit of this architecture base on industry puter (IPC) platform, and is built by plugging in certain control cards and NC software. IPC platform has made CNC unit cheaper and cheaper in price, and easily to be substituted when fault occurs IPCCNC unit CNC system《 NC Technology 》 E－ mail: .Typical CNC Units216。 hence, one CNC unit cannot be changed or substituted by another CNC unit, which is manufactured by a different enterprise. FANUC CNC system, SIEMENS CNC system, and A173。and173。 there is a munication work route between each two microprocessors. Interactions within microprocessors and shared resources are achieved via 173。masterandservant system216。microprocessors architecture216。sharing in a centralized control way.? in this architecture. Some CNC system, though having more than two processors ,can only be called single microprocessor systems, because there is only one micro173。one board architecture《 NC Technology 》 E－ mail: .《 NC Technology 》 E－ mail: .Multi173。 other functional cards are small size, each is installed in a card rack on the main board. 《 NC Technology 》 E－ mail: .Sketch map of All173。in173。in173。in173。NC architecture3. NC173。plug173。functional modules architecture v by the number of microprocessors1. single microprocessor2. multi173。in173。diagnosis function 10. Communication function 11. Programming function 《 NC Technology 》 E－ mail: .Functional interface between hardware and software in CNC unit 《 NC Technology 》 E－ mail: .HARDWARE ARCHITECTURE OF CNC UNIT216。 Tool length pensation, cutter radius pensation , and tool nose radius pensation. 216。 Feed Rate Override216。CNC software controls all functions of the machine and its efficiency of operation, and manages all local programming at the machine tool and graphic simulation of the cutting process if available. 216。CNC unit is the core of the whole CNC system. It is posed of hardware and software. 216。8）診斷： 檢查一切不正常的程序、操作和其他錯誤狀態(tài)。6） I/O處理： 處理 CNC裝置與機床之間的強電信號輸入、輸出和控制。 4）插補： 插補的任務(wù)是通過插補計算程序在一條曲線的已知起點和終點之間進行 “數(shù)據(jù)點的密化工作 ”。 輸入方式 —— 穿孔紙帶閱讀輸入、磁盤輸入、光盤輸入、手健盤輸 入，通訊接口輸入及連接上級計算機的 DNC接口輸入 .《 NC Technology 》 E－ mail: .CNC裝置的裝置的 組組 成和工作原理成和工作原理2）譯碼： 以 一個程序段 為單 位，根據(jù)一定的 語 法 規(guī)則 解 釋 、翻 譯 成 計算機能 夠識別 的數(shù)據(jù)形式，并以一定的數(shù)據(jù)格式存放在指定的內(nèi)存 專用區(qū)內(nèi)。并 進 行 實時 位置反 饋 控制，使各個坐 標(biāo)軸 能精確地走到所要求的位置。2. 軟件結(jié)構(gòu) ： 是一種用于零件加工的、實時控制的、特殊的（或稱專用的）計算機操作系統(tǒng)。從外部特征來看， CNC系統(tǒng)是由 硬件（通用硬件和專用硬件）和軟件（專用） 兩大部分組成的。從自動控制的角度來看， CNC系統(tǒng)是一種位置（軌跡）、速度（還包括電流）控制系統(tǒng)，其本質(zhì)上是以多執(zhí)行部件 (各運動軸 )的位移量、速度為控制對象并使其協(xié)調(diào)運動的自動控制系統(tǒng)，是一種配有專用操作系統(tǒng)的計算機控制系統(tǒng)。vISO(國際標(biāo)準(zhǔn)化組織 )的定義 : “數(shù)控系統(tǒng)是一種控制系統(tǒng)，它自動閱讀輸入載體上事先給定的數(shù)字，并將其譯碼，從而使機床移動和加工零件 ”。 The NC machine :1. control unit, which processes the mands from the input media. 2. the drive mechanisms3. the machine itself 216?！? NC Technology 》 E－ mail: .?? Numerical Control Technology ??機電工程學(xué)院主講： 蔣廷彪 《 NC Technology 》 E－ mail: .Ch4 COMPUTER NUMERICAL CONTROL UNIT 《 NC Technology 》 E－ mail: .Outline system ARCHITECTURE OF CNC UNIT Software4. OPEN ARCHITECTURE SYSTEM FOR CNC UNIT《 NC Technology 》 E－ mail: .Introduction vMachine controls are divided into two types:v numerical control (NC) v puter numerical control (CNC). vNC controls have to read the program each time a part is run。 they have no means of editing existing programs. CNC controls can store and allow editing of loaded programs.v All machines built today are CNC machines. CNC unit is the heart of CNC machine.《 NC Technology 》