a98, i70, RayControl installation issues

[Doug McEwen]

Chuck: In the above thread, I have an a98 as my primary MFD, and an older backup Navman 5380 chartplotter configured to provide a backup GPS source to the a98 via NMEA 0183. Data source selection currently works perfectly between the internal GPS source and the backup GPS source.

My SPX5 course computer is currently configured to forward heading to the a98 via NMEA 0183, which stops the SPX5 from getting a software update from the a98. In the above thread, you state that it would be better configure the SPX5 to forward heading via STNG to the a98, which would permit software updates to the SPX5. But in the following post: http://forum.raymarine.com/showthread.php?tid=107 you state that an data source selection is not possible in a system which includes an SPX autohelm. I assume this means "in a system in which the SPX autohelm is connected to the MFD via STNG". If I am interpreting this post correctly, it suggests that I have to choose between using STNG which allows for software updates to the SPX5, or using NMEA which allows data source selection for an alternate GPS source.

Am I interpreting this correctly? Thanks in advance for all the helpful advice in this forum.