The icusb2322f 2 port usb to serial rs232 adapter cable with ftdi chipset and com retention converts an available usb 11 or 20 port into 2 rs232 serial db9 ports to connect monitor and control your serial devices this compact adapter features com retention allowing the same com port values to automatically be re assigned to the port if the cable is disconnected and re connected to the host computer or if the system is rebooted unlike most usb serial adapters this one uses the ftdi chi