>I started with 9600 since that is what the old device used. In fact I have tried every setting between 9600 and 256000 but all with the same result: no response from the device.
>
>The manufacturer says that the baud rate for the new device is 230400.

Maybe the manufacturer has a solution. They can't be selling this to non-Windows users only. Their tech support must have run into this a thousand times; they may even have a FAQ somewhere.

If MS is obsolete, try elsewhere.