support for Optelec convertcard  #6731

Hi. I have an braille wouager and a Optelec convertecard wich makes it possible to use braille voyager for newer computers. I am not expert, but as i understand it, the card convert braille voyager and even other older braildisplays from Tieman to a newer protocols like alva.
However this card is working on jaws, Windows eyes, and other screenreaders. However nvda does not work with this card. I believe it is more then me who have this issue, a new brailledisplay is not the cheepest eithem you can buy. so support for this would be an good idea. I am not a programer, but i'm not believe this is an bigger task to fix. That could be integrated in that allready alva drivers wich is allready included in NVDA.