... from PV panel through SUNFINE SM to transform single phase pure sine wave AC power feed-in grid ... it displays much more detailed information, such as: current, voltage, frequency from solar panel to public grid ... all the way 4: 9 kinds of protection, for current, wiring, voltage, frequency, AC short-circuit etc. ... far away from users. 7: Used digital phase-locked loop(digital PLL),it has less interference ...