Outer Limits 4x4 Board

I have a garmin 3006c and an 172c, i want to connect them together so the waypoints are shown on both.

I believe i only need one antenna connected but please confirm that too??

Is it as simple as connecting the outpu-input on the respective unit or is there any "programming" or set up issues as well?

contact johnny appleseed GPS they will be able to answer all your questions