Welcome to the Raymarine Technical Forum Jack,
Fluxgate compasses are interfaced to autopilot course computers, not to autopilot control heads. The ST6001 is a autopilot control head which is compatible with a large number of autopilot course computers. What model of autopilot course computer is installed on your boat?
Yes, that is a Smartpilot S1 course computer, the M81190 fluxgate compass will work with that course computer.