Access Control systems are mainly used to restrict access to a property or building. They determined who is allowed to enter or exit, as well as the time and dates this is authorized. Instead of strictly keys to control access, usually proximity or magnetic cards, or keypad combinations are used. hese are usually tracked and recorded for auditing proposes. When the card or combination is presented to the reader or keypad, and access is granted it will open the lock for a predetermined amount of time. If access is refused the door remains locked and the attempt is recorded.