I have a device that communicates with a pc in 28800 bps on rs232.
It has a software to activate it and it works. I want to write my own
software to activate it. The problem is, I can't set the baud rate to
28800. If I look in the device manager, the closest rates are 19200
and 38400. If I open hyper-terminal I see the same. I used a sniffer
and the software sucessfully sets the rate to 28800 so it can be done.
I also tried writing my code in c++ using win api and in java using
rxtx, and none worked in this rate (they worked for other rates).
rxtx actually rounded baud rates to the ones I mentioned above.
What can I do to talk to this device?

I hope the researchers will forgive me for tackling this one ( I am
not an official researcher so this is not answer), but it looks like
no-one is touching this one.

Almost all modern comms devices use a DTE (Data Terminal Emulator)
mode that acts as the physical interface between the device and the PC
use rs232c. For example any 28,800bps modem can connect at 38,400 DTE
speed to the host, and then convert the data stream internally to the
correct baud rate.

If your device does not support DTE connections, then I suggest you
try Procomm Plus from Symantec - see www.symantec.com/procomm. Many
years ago, this product offered intermediate data speeds such as
28,800 bps. However, I haven't used the product for more than a decade
so please check for yourself before buying it.

Tim