Xcbl To IDoc

Hi all,
we are using SAP-BC. we are getting an Xcbl file through FTP location for which we have to map to Orders Idoc. While mapping the segments we are able to get the data for some segments like E1EDK01,E1EDKA1. I’m not able to get the data for Item details i.e . the segment E1EDP01.can anyone guide me.
Thanks in advance,