Description and Identification of STEP Product Data with XML

In order to realize the representation of STEP with XML, taking STEP part 21 file as primary reference, we established the correlation between EXPRESS and XML. In order to realize the generalized representation, we created XML DTD which was based on the hierarchical tree structure for data instance. At last, with the help of SX_Viewer, the process and result of conversion example is presented to verify the feasibility and practicability of this approach.