[TG] Controlling a SmartPilot S3 with Axiom 9

[boxxy]

Hi, I've been searching the forums for info on controlling legacy SeaTalk/NMEA0183 autopilots with an Axiom plotter, but the most recent info I could find was 2014, suggesting that unless it was an Evolution autopilot then it wasn't possible. I have a 10 year old boat with ST290 instruments, autopilot & controls, with 2 i70's to replace the old s60 displays at the helm, and an Axiom 9 at the nav station. These are interfaced to the instruments with an ITC5, and connected together with a SeaTalkng bus. I have the original E80 chartplotter at the helm, but the buttons on it are now playing up and I cant use it as my backup to control the pilot.

My question is firstly (and most importantly as we're about to cross the Pacific), if my ST290 autohelm remote controller dies, I need to be able to control the autopilot - how can I do that with the Axiom?

Secondly, we've now got both SeaTalk and SeaTalkng busses running for'd and aft on the boat - can I simplify this for efficiency and simplicity, to just the ng?

Your advice would be appreciated! Cheers.