【文章內(nèi)容簡介】 nd coordinate the operations of servant microprocessors. 中國電子科技集團(tuán)公司科技與質(zhì)量部 *《 NC Technology 》 E－ mail: Bus based multi CPU system 中國電子科技集團(tuán)公司科技與質(zhì)量部 *《 NC Technology 》 E－ mail: Special purpose architecture CNC units of this architecture are designed and manufactured by different enterprises respectively. They have convenient layouts, pact structures, and high performances for special purpose, but have no general characters。 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。B system (American) are of this architecture 中國電子科技集團(tuán)公司科技與質(zhì)量部 *《 NC Technology 》 E－ mail: Personal puter architecture 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中國電子科技集團(tuán)公司科技與質(zhì)量部 *《 NC Technology 》 E－ mail: Typical CNC Units216。SIEMENS (German)216。FANUC (Japan)216。 ALLEN173。BRANDLEY (American A173。B) 216。 HNC (HuaZhong Numerical Control system216。Blue173。Sky (ShenYang Institute of Computing Technology) 中國電子科技集團(tuán)公司科技與質(zhì)量部 *《 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 *《 NC Technology 》 E－ mail: User software216。User software is also called part program, which is programmed and inputted by using numerical control language (such as APT) to indicate the machining procedure of the part. It is piled into a program with various G173。codes and M173。codes arranged according to the process sequence. 中國電子科技集團(tuán)公司科技與質(zhì)量部 *《 NC Technology 》 E－ mail: System software CNC system software can be sorted into two packages: managing software and control *《 NC Technology 》 E－ mail: The function of control software (1) Compiling the part codes inputted by users After receiving the part codes, piler will translate, trim and store them into a specified format。 decode the machining instructions in part codes and do decimal173。binary transitions to coordinate data。 calculate tool39。s center path considering the offset of tool radius。 pre173。calculate some constants that will be used in interpolation calculation and speed control process, etc. 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 (2) Interpolation calculations Interpolation calculation subroutine has the same functions with hardware interpolator in NC system,!, e. ,to assign electrical pulses for axes. It is a strict real time program, and demands as less as possible number of instruction codes, that is to say, to shorten the time for performing interpolation calculations ,because the time is determinative to the feed speed of interpolation. In some CNC system ,it is adopted to bine rough interpolation and fine interpolation 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(3) Tool pensation All types of CNC machine tools require some form(s) of pensation, such as tool length pensation, cutter radius pensation, and tool nose radius pensation. Though applied for different reasons on different machine types ,all forms of pensation allow the CNC user to allow for unpredictable conditions related to tooling. Generally speaking, if the CNC user is faced with any unpredictable situations during programming, it is likely that the CNC control manufacturer has e up with a form of pensation to deal with the problem.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(4) Speed control 216。 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。 While there is an unexpected abrupt changing in velocity during machining, the speed control subroutine should automatically speed up or slow down the velocity to a