If a proper physical connection has been established between a USB audio device, such as a laptop computer and a Xilica USB device, yet no audio is transmitted or received at the DSP, or no mute or volume sync is present, it’s very likely that the USB card or Gio USB firmware is out of date.
To update the USB card firmware:
Download the appropriate firmware from the Device Firmware Manager in the Xilica Designer software, then right-click the associated DSP and choose IO Card Update (All)
 

For further instructions see the following video: Troubleshooting & Updating USB Audio Card
 

To update the Gio USB firmware:
Download the appropriate firmware from the Device Firmware Manager in the Xilica Designer software, then right-click the Gio USB and choose Firmware update.