That's normal behaviour for a device of this type E., the OS is designed to see a serial connection as a network interface, you can simply ignore this. If the driver you've installed is FCP compatible and working correctly then I believe you should see your adapter as an available device control option in FCP.
Usb To Rs232 Cable For Cnc Machines
Usb To Rs232 Driver For Mac
Compliant with USB 1.1 specifications; Supports RS-232 serial interface; Supports up to 500kbps data transfer rate; Detects USB suspend condition; Compliant with Windows 7/Vista/XP/2000/ME/98SE and Mac OS 10.110.6. I found an old Wacom table with a serial plug. Riva tuner for mac. I would like to connect it to my G5 or Mac Pro. You can get a USB to RS232 adapter but the manufacturer lists only PC compatibility.