please only use the latest or the added manual with your inverter. Growatt has a weird strategy with their devices and had several hardware and software changes within the SPF devices group. On outer cover of your inverter manual you can see on the lower right corner a Version. Latest version for now I know is V4.0. If you have a inverter delivered with this version of manual don´t use older online manuals for this devices as the parameters and other information could have been changed.