The Pro XS doesn't connect directly to NMEA2000 from what I understand. You'll need at least a N2K gateway module from Mercury. THEN your boat's NMEA2000 (N2K) network attaches to that. There could be other cables or components you need; I haven't done this yet myself. But, I do know it's not a direct connect like you're probably assuming/hoping.
The following Lowrance document lays out the options and what is needed. They must have gotten tired of the questions. LOL Connect Mercury Pro XS to Lowrance N2K