By all means, "in Oracle" is EXTREMELY vague : you want to to do it in the db server, inside the database ? In a client machine ? Using WHAT programming tool ? What is the SO and hardware (I suspect Windohs intel-like, "COM port" is wintel lingo most of the times). Being win, and using PL/SQL : Pl/SQL does not have anything native to do it, you will need to call win APIs for this, search the net for "capture com port" , you will find some links.