You may try the German SEW Eurodrive documentation site. The USA site doesn't have this info (unless they changed it). Got to seweurodrive.de, and chase down the link for "dokumentation". They have wonderful, highly technical PDF files that may be of some use. I was told, however, that the positional accuracy between AC induction motor with inverter drive and servo is neglible, AC induction much less expensive. But servo is for high speed motion.
TygerDawg