Alarms are activated on the stairway doors. THIS FUNCTION IS IN OPERATION AT ALL TIMES EXCEPT IN THE EVENT OF AN EMERGENCY. Any time the fire alarm is activated the locking system is deactivated permitting free egress.
This system is designed to enhance security, i.e. you cannot open the door from the corridor side without sounding an alarm and waiting 15 seconds. You cannot open the door from the stairwell side without a key. This means if you enter the stairwell you cannot get out except at the fire exit level.