PLY from Orbec Astra

I am evaluating the Orbec Astra S, but in order to do the analysis of the captured data I need the pointcloud to be in a standard format like *.ply. Because the sdk is based on openNI I was able to save the pointclouds to *.oni file but unable to find any tool to convert it to other formats. Do you have any suggestion to save Orbec Astra S captured data directly to other pointcloud formats or any tool to convert oni to ply.