This study explores the feasibility of variable feedrate parametric interpolators for real time motion command generation using a digital signal processor. Most of the existing parametric interpolators are developed for a constant federate due to the computational complexity. However in certain applications, in order reduce the deterioration in accuracy of machining, feedrate commands should be performed in advance to overcome excessive acceleration and deceleration of CNC machines. The aim of this study is to develop a real time parametric interpolator with variable federate where acceleration and deceleration planning on the feedrate command is performed before the interpolation takes place. This approach that would provide new capabilities for advanced CAD and CAM systems, can compensate for the path command error caused by the acceleration and deceleration after interpolation. To justify the performance of the real time control interpolator, an XY table driven by two servomotors is controlled to track a parametric curve represented in non-uniform rational B-Spline form.