serial-to-USB eblock

I’m trying to connect a bar code reader to FEZ Panda II through a serial-to-USB eblock. But using
"USBHostController.DeviceConnectedEvent += DeviceConnectedEvent", the device isn’t seen and an exception is thrown.
Can someone help me?

serial-to-USB eblock is a USB “device” not “host”. It is made to connect to a PC not to USB devices.

Your barcode reader should be connected ot panda II USB port instead. See this