The C + E Series Widescreen Multifunction Displays had three NMEA0183 Ports, although only two of the ports were bi-directional (input and output), the third port only having an input.
It should also be noted that only one of the two bi-directional ports could be set to the high speed 38400 baud rate for AIS, so it is best not to connect the Sonar Server to this port, if you intend to fit an AIS unit at a later date.
We recommend fitting the Sonar Server to Port 1 as shown in the wiring diagram by clicking here.