how to interface the Weigh Bridge System with ABAP thru' RS232 PORT

Hi ABAP Gurus,

I have to capture the GROSS WEIGHT and TARE WEIGHT from the RS 232 PORT into SAP.

How to interface the Weigh Bridge System with ABAP thru' RS232 PORT.

Can any one plese provide me the code. What BAPI has to be used. I want to capture the GROSS WEIGHT and TARE WEIGHT in the MIGO (GOODS RECEIPT) Transaction Screen.

Thanks in advance

Jacob S.