Solar to power sub panel with auto transfer switch grid backup. What to do with Neutral and Ground?

brad196565

Brand new to Solar.  Plan to power a new subpanel to run minisplit air and a few other circuits.  I want to have grid as backup for subpanel in case pv system has issues.  I have 120/240 split phase inverter, solar cells, batteries, and autotransfer switch which can isolate 3 poles and a Neutral.  I have read seemingly conflicting statements about connecting my inverter neutral and ground to my main panel's neutral and ground.  Not sure what to do.  I plan to use grid power for main panel and solar for subpanel at the same time. Live in Florida, USA.  Your help would be greatly appreciated.  Thank you