XML implementation of STEP-NC data model

STEP-NC is a newly developed international standard(ISO 14649) for Numerical Control(NC) programming,and ISO 10303 Part 21 physical file is the common format of NC program generated through the STEP-NC standard.However,the file format is not easy for interpretation and transferring information over World Wide Web. To deal with this problem,the method of adopting eXtensible Markup Language(XML) as file format of NC program was proposed.Key concepts of STEP-NC data model and shortcomings of STEP-NC numerical control program in the Part 21 physical file format were analyzed.Then how to generate the NC program of XML file format was studied including selecting file structure,mapping from EXPRESS to XML.Next,the XML file was used as the input of CNC controller.Software of CNC controller was divided into three modules,namely interpretation of NC program in XML,micro process planning and automatic generation of tool path,and generation of NC instructions for Machine Tool Motion.For the three modules,the first one was studied in particular.