The DEPFET Collaboration pursues the development of a high resolution pixel vertex detector for future colliders (like ILC), based on the integration of amplifying transistors into a fully depleted bulk. In August 2008, six DEPFET prototypes were tested in a pion beam at SPS complex at CERN, collecting more than 20 million of events. In this contribution, the prototype system, the experimental setup, the analysis software and preliminary results are presented. ; Comment: 3 pages, 3 figures, LCWS08 conference, tracking and vertexing session