Mandatory fields in BAPI

Hi,

while I am trying to post unexpected events using FM /SAPTRX/BAPI_EH_ADDEVENMSG_02, I can post unexpected Events against the freight unit execution tab, but the location, actual date and time is empty. Also, I would like to specify the source of the message (PhoneApp or even better phoneapp AND Driver id). Which fields do I have to fill in  structures TRACKINGHEADER, TRACKLOCATION and TRACKMODIFY.

Thanks in advance for your help.

Regards

Petra