[rirvine]

There is only one GPS in my system (RM GPS). Because RM does not do very good job of converting Seatalk to NMEA in their convert box (many fields in the sentances are null), I use the NMEA output (contains more data) from an SC520 chart plotter for the GPS panel in MacENC and the NMEA from the convert box for the instrument panel in MacENC.

Because Seatalk in a multi-drop buss, it (and hence the NMEA output from the convert box) contains a lot of sentances that has nothing to do with instrument data (including GPS related data) that needs to be removed for TCP/IP.

Hope this is clear,
Ray