I don't know about this particular unit, but when I setup my CSB200, I had to do the same thing. But since I don't have a 9 pin
serial port on my laptop, just USB, I first had to install a USB to
serial adapter. It was plug-n-play, so windows installed the driver for me and, in my case, indicated it was on com24.
So, when I ran the AISPro
software, and it asked me which com device, I just selected com24. The
software also indicated which pair was AIS and which was
NMEA. In my case, I had to change the
NMEA from the default of 38.4k to 4800 (or whatever it was).
Your software should
work in a similar way. How did you connect it to your computer?