Yes, the 1197c Si is able to be connected to an NMEA 200 system using the AS-ETH-NMEA2K accessory.
The NMEA 0183 data sentences that the 1197c Si outputs is:
GLL - Geographic Position - Lat/Lon
GGA - GPS Fix Data
RMC - Recommended Minimum Specific GNSS Data
VTG - Course Over Ground and Ground Speed
ZDA - Time and Date
APB - Autopilot Sentence B
BWR - Bearing & Distance to Waypoint - Rhumb Line
RMB - Recommended Minimum Navigation Information
DPT - Depth
MTW - Water Temperature