By way of clarification, note that the NMNEA 2000 connection for the autopilot is made from the processor. The control heads each connect to the processor and have access to NMEA 2000 data. But the 711C is not like some other autopilot systems that use NMEA to connect the control heads.
However, note that once you have made the NMEA 2000 connection to the processor a Furuno MFD will be able to control the autopilot too. It would have been a big undertaking to run a new cable from a control head at my tower helm. Instead I use the TZT 10X MFD up there to control the autopilot.
We looked into using an existing NMEA 2000 cable for a control head. There are six wires in the Furuno cable for the control head and only five ina NMEA 2000 cable. It might have been possible to reuse the cable with a little creativity by suppling a separate ground but we decided it wasn't worth the risk.