DATA ISSUE IN RFD900x

I have 2 RFD900x modules,I’m Sending the 1400 bytes of Data at a time using Packet Format and Receiving 1400 bytes of data Exactly but the issue is i’m sendig 1400bytes of data in a single packet,i’m receiving the 1400bytes of data is splitted into no.of packets,

How can i overcome this issue,is there any settings to overcome this issue,if it is possible to overcome please explain clearly,if not what is the solution for this issue.