Access Control

Access Control

In the fields of physical security and information security
access control (AC) is the selective restriction of access to a place or other resource
while access management describes the process. The act of accessing
may mean consuming, entering, or using. Permission to access a resource is called authorization.

Locks and login credentials are two analogous mechanisms of access control.

Access control system components

Various control system components
Components of an access control system include:

An access control panel (also known as a controller)

An access-controlled entry, such as a door, turnstile, parking gate, elevator, or other physical barrier

A reader installed near the entry.
(In cases where the exit is also controlled, a second reader is used on the opposite side of the entry.)
Locking hardware, such as electric door strikes and electromagnetic locks

A magnetic door switch for monitoring door position

Request-to-exit (RTE) devices for allowing egress. When a RTE button
is pushed, or the motion detector detects motion at the door, the door alarm is
temporarily ignored while the door is opened. Exiting a door without having to
electrically unlock the door is called mechanical free egress. This is an important
safety feature. In cases where the lock must be electrically unlocked on exit,
the request-to-exit device also unlocks the door.[11]