The Garmin 17xgps (?) is a
NMEA 2000 based unit and comes with everything needed to create a small N2000
network. Therefore the RM GPS won't
work directly with the 4210. You can do all of this though, you'll just need to put in a
Nmea Multiplexer to connect the instruments to and then to the 4210. (The ST60s do put out a
nmea 183, don't they?) Not too difficult. If you don't exceed the Garmin's inputs you don't need the multi. The 4210 can recieve the
AIS signal directly, but you have to configure the baud rate. And the 4210 will feed info to the AP.
I just did the same thing with Nexus instruments and a
Simrad AP, a SmartRadio AIS, lots of
wiring, but no problem.
Dwain