gps datum error

[Murfmv@gmail.com]

When I go through the setup commands, specifically the data logs, all items show something besides auto except gps datum.I'm using a miniplex 3wi-2NK multiplexer to deliver the gps data to autopilot, and depth and speed from ST60 triad through seatalk1 to my EV400, newly installed autopilot via SeatalkNG. When I check data logs, each variable defines where the data is coming from. Depth was not coming across and the people at ShipModul, found a firmware problem and fixed that.
Everything is working marvelously, except when I get to data log for gps datum, it searches the network and finds nothing, so all I have is auto, therefore nothing is coming from the gps.

First, how important is ""gps datum'' value to autopilot? How will this loss affect performance? I want to know before I asked ShipModul to fix this problem.

One other item. When I add the rudder sensor to the EV400 system, do I have to reset the system and start over and lose the vessel adaptations the brain has made to the vessel or can I just go to commissioning and just recalibrate the rudder sensor?

Fred