The multi PDU approach simplifis low-level software driver designs [1.] In the CiA 602-2 application layer (J1939 on CAN FD) several i-PDUs containing legacy J1939 parameter groups can be mapped into a single CAN FD frame [6.] The CAN-ID contains the Source Address (SA), the remaining elements of the PDU identification are in the 24-bit i-PDU header.