No messages return from CALL TRANSACTION ABZON

Hi all,

I'm implementing an BDC program for multiple asset txn posting with tcode ABZON. If there's an error during the posting, I can get the detail system messages. However, nothing was returned from it if posting was successful. The sy-subrc is 0 but the messages internal table contains no line. Appreciate if any experts can tell me what I missed. Hereunder is my ABAP code:

call transaction 'ABZON' using xbdcdata mode p_mode update 'S' messages into xbdcmsg.

Thanks a lot in advance.

MH.