0183 Route into VX2

My new boat comes with a pair of networked 10.4" NavNet vx2. But I want to carry over my previous GPSMAP 741xs for route management (GPX format compatible, auto-routing, iphone downloadable, etc.). Can I feed real time route/waypoint data into the vx2 via 0183?
My set-up (I think):
Network Plotter GD-1920C Lower Helm:
Port 1 Input from GPS Antenna
Port 2 Input AIS from Horizon GX2100
Port 3 Unused
Port 4 Output to autopilot & GX2100
Network Plotter GD-1920C Upper Helm:
Port 1 Unused
Port 2 Unused
Port 3 Unused
Port 4 Unused

Thanks

Yes the manual calls it external waypoint. The Vx2 can take external waypoint via NMEA 0183.

Which data ports can accept external waypoints?

On a 10.4; data 1 , 2 , OR 4 as long as you setup the setting for external waypoint. Think it requires RMB if I remember correctly.