【正文】 How many types of CNC units exist depending on the number of CPU they include? What is the character of each type?216。3）網(wǎng)絡(luò)化中國電子科技集團(tuán)公司科技與質(zhì)量部 *《 NC Technology 》 E－ mail: Homework 216。：1）在控制系統(tǒng)技術(shù)，接口技術(shù)、檢測傳感技術(shù)、執(zhí)行器技術(shù)、軟件 技術(shù)五大方面開發(fā)出優(yōu)質(zhì)、先進(jìn)、適銷的經(jīng)濟(jì)、合理的開放式數(shù) 控系統(tǒng)。station/Machine Controller)和 OMAC(Open Modular Architecture Controller)計(jì)劃– 歐共體： OSACA（ Open System Architecture for Control within Automation Systems)計(jì)劃– 日本： OSEC(Open System Environment for Controller)計(jì)劃– 華中 I型 —— 基于 IPC的 CNC開放體系結(jié)構(gòu)– 航天 I型 CNC系統(tǒng) —— 基于 PC的多機(jī) CNC開放體系結(jié)構(gòu) 中國電子科技集團(tuán)公司科技與質(zhì)量部*《 NC Technology 》 E－ mail: 國內(nèi)外開放式數(shù)控系統(tǒng)的研究進(jìn)展國內(nèi)外開放式數(shù)控系統(tǒng)的研究進(jìn)展 ：1） CNC可以直接地或通過網(wǎng)絡(luò)運(yùn)行各種應(yīng)用軟件2）用戶操作界面的開放?？蓽p少產(chǎn)品品種 ， 便于批量生產(chǎn)、提高可靠性和降低成本，增強(qiáng)市場供應(yīng)能力和競爭能力 。向用戶特殊要求開放： 更新產(chǎn)品、擴(kuò)充能力、提供可供選擇的硬軟件產(chǎn)品的各種組合以滿足特殊應(yīng)用要求，給用戶提供一個方法，從低級控制器開始，逐步提高，直到達(dá)到所要求的性能為止。 向未來技術(shù)開放： 由于軟硬件接口都遵循公認(rèn)的標(biāo)準(zhǔn)協(xié)議，只需少量的重新設(shè)計(jì)和調(diào)整，新一代的通用軟硬件資源就可能被現(xiàn)有系統(tǒng)所采納、吸收和兼容，這就意味著系統(tǒng)的開發(fā)費(fèi)用將大大降低而系統(tǒng)性能與可靠性將不斷改善并處于長生命周期；216。體系開放化 定義（ IEEE）： 具有在不同的工作平臺上均能實(shí)現(xiàn)系統(tǒng)功能、且可以與其它的系統(tǒng)應(yīng)用進(jìn)行互操作的系統(tǒng) 。 There is no distinction of background and foreground applications in this architecture. Except for initializing procedure, this architecture divides all control programs into interruption service procedures with different priorities, so that bees a large multilevel interruption system. 216。second, initializing process216。The system program can be generally carried out in the following courses:216。 background application is a loop running program, which realizes the input of part program, do some preparatory processes and manages tasks of procedures. 216。 CNC system software: foreground application and background application. 216。tandem architecture216。It manages and coordinates each executing of tasks in proper time order and logical relationship to meet the control needs of CNC system.216。software interruption中國電子科技集團(tuán)公司科技與質(zhì)量部 *《 NC Technology 》 E－ mail: Architecture of CNC System Software 216。hard173。external interruption216。Interruption technology is the main feature of real time process. 216。sharing technology and time overlap flow line technique are mainly used in software designing. 中國電子科技集團(tuán)公司科技與質(zhì)量部 *《 NC Technology 》 E－ mail: Real time process216。microprocessors architecture to improve process speed. 216。Nowadays, resource173。sharing technology is based on time173。apposition （ 資源重復(fù) ）中國電子科技集團(tuán)公司科技與質(zhì)量部 *《 NC Technology 》 E－ mail: Time overlap methodv Time overlap method, based on flow line technique, staggers the processing time of procedures, and makes many procedures use parts of the equipment respectively at the same *《 NC Technology 》 E－ mail: Resource173。sharing technology （ 資源共享）216。Time overlap method (時間重疊 )216。Parallel process means that puter implements two or more tasks at the same time or within the same time interval. It can improve the processing speed greatly. 216。 management, which are all real time tasks. 216。 Managing software can be divided into two groups: one prises the subroutines that tie to hardware, and another is independent of hardware. 216。 and diagnosis codes ,by which CNC unit can carry out self173。Managing software is posed of part program I/O。zero when reverse the motion, so that the location precision would be improved. 中國電子科技集團(tuán)公司科技與質(zhì)量部 *《 NC Technology 》 E－ mail: Position control中國電子科技集團(tuán)公司科技與質(zhì)量部 *《 NC Technology 》 E－ mail: Managing Software 216。return173。 This work can be done by either software or hardware. Position control software pares interpolation calculated position with real measured position in each sampling cycle, and control the motor using the difference. 216。 Speed control can be implemented totally by software method (software timer method), and can also be implemented by hardware means. 中國電子科技集團(tuán)公司科技與質(zhì)量部*《 NC Technology 》 E－ mail: The function of control software(5) Position control216。 Speed control subroutine aims at controlling the speed of pulses assigning, . controlling the frequency of interpolation calculation according to the setting speed code (or corresponding speed instruction) to guarantee the preset feed velocity.216。 pre173。 calculate tool39。 decode the machining instructions in part codes and do decimal173。codes and M173。Sky (ShenYang Institute of