Where does the built-in GX device get its power supply from if you want to remotely update the firmware to an e.g. EasySolar or MultiplusII-GX? Considering "Confirm that the GX is not powered by the inverter. In order to remotely update the firmware on the VE.Bus system, it is important that the GX is not powered by the inverter." Grateful if someone can clarify the matter.