Originally Posted by Alex W
Standard Horizon's NMEA 0183 seems to be particularly busted in general. I'm happy that there are alternatives to the GX2100 showing up on the market (like the Lowrance Link 8 and similar Simrad model) that don't require 3 unidirectional serial ports...
I have the GX2150, not the 2100, but I'm almost 100% sure that you do not need three separate serial ports. I believe that you can group the 4800 in and 4800 out onto one bidirectional COM port.
On the 2150 you can alternately get all three (AIS out, DSC out, GPS in) onto one port at 38,400. I don't currently use this feature (because my autopilot only works at 4800), but it is one of several reasons why I waited for the 2150 to come out.