I purchased a RDP 148 several years ago, I have used it as a standalone chartplotter/radar by its self. I purchased a Stan. Hor. DSC/AIS radio and want to hook it up to the Furuno, When I went to the menu to select the NMEA sentences Data Port 2 is not there, Port 1,3 and network show but not 2??? any idea as to why it is not showing up? Also I need to have the software updated as it curently has 01,06.