Hi all :
I come across to use the Catalyst Switch 2955 and it has two Relay Connector with one Major (MAJ) and one Minor (MIN) as below picture.


There is command line to trigger these two Relay Connectors. As below command to set the Relay Connector to minor for monitoring the power supply :
alarm facility power-supply relay minor
1. My questions are when there is power-supply faulty, the Minor Relay Connctor (right picture) will be short-circuited, right?
2. If we connector the two ports (ports 4 & 5 at the left picture) with a normal cable to drive an Alram Bell (in short-circuiled or closed loop situation), do we need an external power supply to the Alram Bell? Or there will be power supply from Catalyst 2955 to the Alram Bell as well?
Thanks!
Best regards,
tangsuan