Michigan Muskie Alliance

Maybe poor ol'finlander can find help here. I bought a pair of Lowrance 520c's. The set came with an Ethernet cable that will allow one to view the other 520's sonar. I could be in back trolling with the bow mount transducer down, and watch the sonar return on my rear mounted screen. Does anyone here have Lowrance's, with that type of setup, and would know HOW I can bring up the others sonar return? Thanks for any help you may provide.