An access control system allows authorized users to enter a building or areas inside a building by authenticating their access. Simply, an access control system is used to open a locked door using electrical/ electromagnetic locking systems via relays and automatically locking the door after the user has entered.
There are different types of readers that can be used on their own or in combination with each other with door access control systems. For example, you can install a smart swipe card or FOB reader, or even readers that scan biometric identification details (like fingerprints) or (Eye Recognition).
In smart cards, there are a set of unique codes for each employee that are embedded in the card. The access control reader checks the code read from the smart card, which is then verified from a centralized database located on your network. If there is a match it will activate a relay circuit which unlocks the door so that the person/employee can enter.
For more than one access point you will need additional controllers and control panels, as well as electrified locks. Some doors may also need additional hardware to make the door access ready. You should check with your local AHJ inspector before installing any door access system, as local codes vary from State to State.