VISA has all of the tools you need to send and receive data over the
serial port. If you know all of the commands and the data format, then
yes, you should be able to create your own driver. If the vendor has
provided a driver in the form of a DLL or ActiveX control, then you
could perhaps use that instead but you would still need some
documentation on any provided software. I went to the Polhemus web
site and didn't see any information on software but if they did
provide some sort of driver, could you explain what you've got in
detail?