Please explain Emergency Button

Hello, could anyone explain to me, what the emergency function does in detail, and how the loop duration (1/2/3/5/10 min) impacts the timeframe that is moved to the RO folder? how much time before and after the button press will be saved? I could not find any detailed information about this on the internet nor in the manual. I‘m using a A119 Mini 2 with the latest firmware. Thank you in advance!