Research On The Implementation Methods Of NC Programming Based On STEP-NC

STEP-NC, based on STEP, is established by the International Standards Organization.It isused in the field of CNC programming interface, defined as ISO14649. It achieve informationtransform amang CAD/CAM/CAPP system in the life cycle of product.New CNC standard isdiffrerent with traditional standard,STEP-NC not only have all geometric information ofparts,but also have manufacturing information.It play a role of modern manufacturingindustry.This paper analyzes the development of new CNC standard,the advantages of STEP-NCstandard numerical standards and the restrictions bringed by traditions.Analyzing theSTEP-NC program structre,it leads to the formal language-EXPRESS.This paper alsodescribes the implemetation method of STEP-NC and shows the SDAI method.Visual Basic language is used as a development tool in this subject.Using itscompilation,it builds the mapping relationship between EXPRESS language and VisualBasic.Based on STEP and used Visual Basic,it realized the conversion form STEP toSTEP-NC and transformation form STEP-NC to G / M code.And this subjct put forward twoconcepts:STEP-NC converter and STEP-NC interpreter.STEP-NC converter achieve thetrasform form STEP to STEP-NC, adding product manufacturing information on the basis ofEXPRESS language structural features;STEP-NC interpreter achieve the trasformation formSTEP-NC to G / M code, through information extraction , feature recognition, trajectorygeneration the last generation G/ M code.