I have TWO IF-NMEA2K2 converters on an N2K bus, one for the autopilot and the M-1945 radar (both NMEA0183 devices), and the second for a VHF set (Icom M604, also NMEA0183). The OS position from the GPS/plotter (GP1670F, N2K) reaches the VHF set ok, and DSC positions from incoming VHF calls show correctly on the VHF set itself but they don't get displayed on the plotter. Everything else works, but It looks as though DSC/DSE inputs converted by the second IF-NMEA2K2 are being ignored when they reach the N2K bus.
The GPS tells me that the two IF-NMEA2K2 converters both have the same System Instance Numbers (both 0) and also the same Device Instance Numbers (both 00). Will this stop messages coming from the second IF-NMEA2K2 being recognized on the N2K bus?