The US2 is only a DualBeam 83/200khz transducer and will not provide imaging. If you want to connect a 899ci SI model to the US2, you would need to change the connected transducer to a 83/200khz setting which may be "Generic 83/200khz" depending on available selections. You would also need the minnkota MKR-US2-8 US2 adapter cable.
If you have just basic Ipilot TM, there is no connection to any fishfinder. The Link version is an ethernet connection with compatible ethernet capable Humminbird models. The ethernet connection is not for a sonar connection. Link will allow commands from a Humminbird unit and additional storage space for spotlock waypoints, itracks, etc. Follow the Contour function can only be initiated from a Humminbird unit with a Link model TM and Lakemaster or Autochart map.
https://www.minnkotamotors.com/learn...versal-sonar-2