STEP-NC is a new interface standard for data exchanging and sharing between CAD/CAM and CNC

and the CNC based on STEP-NC will be the next generation of CNC controller

which not only holds linear and circular interpolation but also possesses the capability of spline interpolation.A universal NURBS(non-uniform rational B-spline) based interpolator was designed and the interpolation technique based on constant arc increment and interpolation algorithm were inverstigated arc increment.The validity and reliability of algorithm was tested by an instance simulation and machining.