I have rs232 port but i wants more no of rs232 ports . So i decided to use rs232 converter . I bought it from market and when i connect it turns on device but does not receive data on hyper terminal. And if i connect back it to rs232 port means loop back test it sends and receives data . My device uses 4 pins Tx , Rx , Ground , DTR. It works properly when connected to rs232. Or tell me any more idea to increase com ports(rs232) with out using pci Because i could not get expansion card as there is pci e x1. Port in my machine. Any idea ???????????????????