Calibration multiple magnetometers

Looking at the Mission Planner calibration screen, it shows three mags. There is also a selection whether each is internal or external. The tutorial assumes you know how many mags you have and which are external vs internal. I don’t know this information.
How do I find out the following:

How many mags does my system have? Does it have three or less?
Which ones are internal and which are external? Is there a default number for the mag(s) inside the Pixhawk 2?

I did the initial calibration using only Mag 1 and called it internal, but I’m getting mag error messages in the Auto Log Analyzer.

Hope someone can help with this.

Thanks,
Joe

Your best bet to start out is set the first compass as external and disable the other two. This assumes that you are using a GPS unit. Try calibrating and see if that works. Compass mounted as far away from other components work better than internal compass on the flight controller as they don’t have to deal with as much interference.

Mission Planner>Setup>Mandatory Hardware>HW ID