Sacramento Exit Devices and Life Safety
Any time you see an electrified lock on a door, chances are it is monitored to detect intrusions. When a door opens, it’s considered an intrusion, a authorized exit, or and authorized entrance. These doors have a door position switch, which keeps track of whether the door is opened or closed. The door position switch can not differentiate an intrusion from an authorized entry or exit, it only tracks the open or closed status. The access control panel is where the decision of whether an authorized opening has been made or not. The panel makes this decision by verifying that the credentials entered by the user are correct. The credentials supplied by the user could involve entering a keycode, swiping a card, or interacting with a biometric reader. Once credentials have been verified, the access control panel unlocks the door, makes a record of the event, and bypasses the door’s alarm.
You can program the amount of time you want the access control panel to ignore the door being open. Once the programmed amount of time has passed and the door switch still reports the door opened, a propped door alarm is triggered. A request-to-exit sensor handles door exits. When an authorized user attempts to exit, a similar set of events occurs. The access control panel unlocks the door, records the authorized opening of the door, bypasses the alarm, and starts the door propped trigger event. If someone tries to enter or exit without providing authorized credentials, the alarm triggers. The quality and type of Request-to-Exit sensors used play a large role in preventing false alarms. An entry detailing more about types of Request-to-Exit sensors is coming soon.
For more information about Exit Devices, Life Safety, and all things Access Control check out Thomas L. Norman’s book Electronic Access Control.