Hi Aaron,
CAN stands for Controller Area Network, and it’s the two wire network that the Rotax ECU uses to communicate with other components in the system. If you are using the G3X as your EFIS, then the Rotax CAN is connected to a Garmin GEA24 (engine interface module) to convey instrument and FADEC information to the EFIS. Dynon has a similar architecture with different part numbers.
There is also a separate Rotax maintenance CAN, which is what you use to connect the BUDS dongle and software. What’s more is the EFIS has its own CAN to communicate with other devices in its network. Garmin calls these remote devices LRUs (line replaceable units). There are also serial connections to some Garmin components that are not CAN capable. Complex yes, but this is the stuff that enables all the great features.
