There isn't a direct connection. You'll have to get a Seatalk1 to SeaTalkng converter. Raymarine Part# E22158. Its about $90, and easily installed.

Having just done this, I'd ebay the RS125 and put the $ towards your updated electronics.

With the Axiom+, you may not need an external GPS, but if you do the RS150 is very fast, and a huge improvement over the older Raymarine GPS 's and even the internal one in my Axiom (not a + version).

 

Buy a 150… only way to go if you want external

 

I figured. I’m still using the 125 to run my vessel view and gauges. Not wanting to spend the money to convert everything. Guess I can have 2 gps for now

 

Got my axiom install in the slip with metal roof. Can’t get gps fix, no surprise but I can go downstairs and my iPad gps works just fine.

now that’s frustrating

 

Does the rs150 hooked up on the raynet connector on the axiom get data onto the Nmea 2k side?

 

The rs150 on our setup is connected to STNG and can be seen as a distinct device by everything on that and the interconnected N2K network. The only thing that does not use it is the AIS transceiver that has its own gps.

 

Got my axiom install in the slip with metal roof. Can’t get gps fix, no surprise but I can go downstairs and my iPad gps works just fine.

now that’s frustrating

I had the same issue with my original Axiom 12 under a metal roofed slip, but it wasn't much better outside in the open. Position jumped around, and the speed wasnt accuare/stable. I have my Axiom mounted in a metal adapter plate to fill the gap between the A128 install and the Axiom...I think that made it worse.

I added the RS150, and its is MUCH better. Position is instant, accurate, and the speed is now very consistent. Great upgrade.

I also added an 9" Axiom+. Those are supposed to have a much better GPS, but I have not tried that as the GPS source to confirm it works better than the original Axiom.

Connection is on the STng Network as Henry pointed out. You can also interface to a standard NEMA2000 network with an adapter, depending on what you have.

 

I ended up going with the garmin 24xd. Same price as rs150 but included a 16’ drop cable and tee and has a heading sensor.
Works great