HDS7 gen3 with HDI transducer

[Nitrobird]

I'm wanting to put a hds7 gen3 on the bow of my boat and run a hdi transducer on trolling motor. This will give me 2d and downscan sonar. I want to know if my hds 9 gen2 touch is Ethernet to the hds 7 gen3 can I use my lss2 transducer at the back of boat to view side scan while also viewing downscan on the front transducer. May sound dumb but I would just like to search all around boat for structure while fishing and viewing my 2d and downscan at the same time.

[lowe rider]

The Lowrance units can only view one structure scan source at a time.