Not sure I could think of anything from that panel that would cause an alarm. Typically there would be a smoke dectector, CO2 detector or propane detector that would alarm. Some RVs have an alarm when the tanks (black or grey) get near full but I think those are a beeping not constant. You may also get a low battery warning but again not a constant shrill sound. If you are plugged into shore power you shouldn't have a low battery warning. Sorry I can't direct to the cause.
2011 Escalade 37RE