ICX 7150-24P Stacking Port not staying linked

[ChadSchonrock]

I am trying to get 3 - 7150-24P stacked over a long distance on top of a Ciena 5171 10G transport system and getting the stacking ports are coming up and then go down right away. When they are up, the error is "Port is up in IEEE Mode, not HiGig Mode."

What type of protocols does the ICX 7150-24p running firmware version 08.0.95n use to make the stack connection?

Any help with getting this stack running over this long distance transport system would be greatly appreciated.