It seems that you have worked on FT232R(I have read your post on rabbit forum.) I am trying to implement serial to USB & vice versa communication using FT232BM. Can you please guide me whether I have to use all handshaking signals or only RTS & CTS are sufficient for communication? & if these two signals are sufficient then what we have to do with other handshaking signals(ie. DTR, DCD etc.) Is there any good material which I can refer?