I have a Triaxis also, but haven't hooked it up since I got my Helix. :p
If you're wanting to have Triaxis tone and use the Helix for only effects, signal chain should be: Guitar --> whatever you want in front of Triaxis --> Triaxis Guitar In --> Triaxis L Out (or both for stereo) --> Helix Guitar In --> Helix 1/4" Out --> Power amp. Then run a midi cable from the Helix Out/Thru to Triaxis Midi In. That will take care of the patch changes. Leave amp, cab, and IR blocks alone if you're using a traditional guitar cabinet.
If you want to run direct without a power amp, then the same signal chain above should be fine minus the power amp but add a cab or IR block in the Helix's signal chain.
