NMEA 2000 bus crash

[Chuck - Raymarine - Moderator]

George,

Based upon the system diagram which you have supplied, it does not appear that you have a properly constructed NMEA 2000 backbone. Specifically, the Simnet appears to have been installed as a spur rather than as part of the backbone ... i.e. the RC42, AC28, and AC42 (assuming that these are all NMEA 2000 certified products) should each be installed as an individual spurs to the backbone.

Is its also not clear where the backbone's power insertion point is located. Within a properly installed backbone, the single power insertion point should be located at the approximate midpoint of the backbone's LEN load.

With respect to the system functioning in the past and not functioning now, I can only suggest that it may have been teetering on the edge of the incorrectly constructed backbone's tolerance, waiting for an additional device to push it over the edge.

Finally, with respect to the a75 being configured as a Data Master, this setting only applies to systems featuring an Ethernet network of more than one Raymarine a/c/e/eS/gS-Series MFD. In such systems, only the Data Master MFD will typically be interfaced to the SeaTalkng/NMEA 2000 backbone and it will in turn share data with the other networked Raymarine MFDs. In systems having only one Raymarine a/c/e/eS/gS-Series MFD, the MFD must be configured as the Data Master (the default state of the MFD).