Don''t know much about B&G (Raymarine user for years) but my first guess is that the serial plug would be a NMEA output from your
GPS to a computer for a charting program. If the rest of your instrument are not linked on any kind of a buss they can''t share information with themselves or the computer. They may or may not have this capability. If they are all linked they can share info with the computer so you can get depth and wind info on your computer screen in addition to the
GPS output for plotting purposes if you have the appropriate program. I doubt if it is possible to interface your
radar with the computer.
Raymarine sofware does this with their own
radars and Nobeltec will do it if you use their scanner. In any case it''s an option of little value unless you spend all your time at a nav station. Although the ability overlay
radar on a realtime chart with vessel plotting is nice.