If the ELK P212S Supervised Power Supply is connected to the M1’s Data Bus and set to M1 Mode (jumper between NEG and “M1 Mode Terminal”)  the Definition should be Def – 32 Power Supervisory 24 Hr. The P212S is considered a Keypad Type 1 Bus Device and the address will determine the Zone that will report the AC Fail and Low Battery. In the M1 Mode there is no need to wire the AC Trouble Relay to a Zone.