Thought this might be of interest to anyone adding an A-series MFD to existing Seatalk networks including ST4000 autopilot. You'll need an NMEA to Seatalk converter, but that's the easy part. When I hooked up, all my Raymarine equipment shared data via Seatalk, but my autopilot/fluxgate compass got confused, and the heading display showed a constant heading, no matter which way the boat was pointed. Raymarine tech support sorted out the problem right away: the A-series unit was transmitting bearing data to Seatalk at the same time as the autopilot/fluxgate. The solution is turning off the NMEA "sentences" creating the conflict. I was using Port 1, and turned off all sentences except APB,RMA,RMB and RMC. Problem solved.