ok guys im losing my mind trying to network my ultrex and 2 humminbird helix units. the ultrex , one cable goes to the connector and then into the transduecer port? (built in mega di) then the ethernet cord to the box? do i then need an ethernet cord from that unit to the box? . I know the back unit ethernet cable goes to the box. the heading sensor goes to the box but the front unit is confusing me.

Don click on Humminbird networking diagrams. It shows in detail the wiring route for your set up. 
 

If your Ultrex has I-pilot link then you will need to connect it’s Ethernet cable to an Ethernet switch and each fish finder will also need to have an Ethernet cable connected to the switch. Here is the diagram.

 

https://www.humminbird.com/sites/humminbird_site/files/2021-humminbird-networking-diagrams-2.pdf

I figured it out guys. it was very simple once i realized i had the adapter in the paper work that i needed to connect the ethernet to the depthfinder. of course when i got the motor mounted and was testing the lift and deploy i got the transduecer cable caught in the pinch point and crushed it, but thats life when your stupid you cant have nice things. luckily i have a good mont before the fishing starts to pick up. hopefully i can get it fixed by then.