I have the 9110, but don't see the P_ON setting, just what's in the manual: OVP, OCP, BEEP, ADD, GRP.
ADD stands for address I think. It's asking for which key you want to store the displayed voltage/current setting on. GRP stands for group and you can have many different groups of keys with stored voltage/current values. I think it's just as easy to dial in whatever voltage/current you need rather than use the save/recall memories.
Perhaps the P_ON is a 9111 (only) setting to indicate if the output show be enabled at power on, just a guess.