If you have DLN-2 adapter and want to acquire DLN-2-U2C adapter, firmware can be easily changed.
To upload U2C-12 compatible firmware to DLN-2 adapter, download U2C-12 Compatible Firmware Uploader (dln_2_u2c.exe) from the Downloads section of the www.dlnware.com web site. Plug-in board to USB port, run dln_2_u2c.exe application, choose latest available firmware version and press Upload button to upload firmware to DLN-2 adapter.
Now you have fully compatible U2C-12 board which can work with U2C-12 driver and API.