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 Serial Adapter Cable For Macbook Air
The Sabrent USB to Serial SBT-USC1M converter is the perfect solution for transferring data from a PDA or digital camera. The USB to DB9 provides a connection between an available USB port and the more traditional RS-232 serial port found on many devices. At a block level a USB to serial adapter consists of a USB serial processor chip, a serial driver chip and if the adapter is isolated there will be optocouplers in front of the USB and / or serial ports. The above design consists of a FT2232 USB serial processor from FTDI, which is a dual serial port processor.