some clarification. Fronius' usability depends a lot on the integrator.
Fanuc and Fronius develops the communication together, so there's also a Fronius library as a Fanuc option.
Basically you make a controll start select fronius EthernetIP inside, enter where to start IO-s and its done.
You can use job numbers in the TP programs, or enter each and welding parameter in the weld schedules. Whatever your preference is. You can manage all powersource setting from the teach pendat too. (water cooler, crater fill etc.)
8 mm sheets with a root gap tolerance of 2 mm?
Whats the welding joint geometry?