What is Access Control?

Access control, as it applies to physical security, refers to a system that is used to permit access to authorized people and deny unauthorized entry.  Typically it is used by employers to secure their buildings where employees use a key card or key fob to gain entry.


What does a typical door installation look like?

Access control door wiring

Door Contact

Also called a door position switch, is used to sense whether a door is opened or closed.

Electric Strike

Electric strike, or more generally door locking mechanisms, are the electromechanical or electromagnetic devices that allow the door to lock or unlock.


The reader is usually located on the unsecured side and reads the information typically from a key card or fob, sometimes a keypad or biometric reader.

Exit button

Request to exit, or “REX” devices are used to alert the system that a person intends to leave the secured area.  Alternatively, a reader can be placed on the secured side to issue the same request.

Control Panel

The control panel or “controller” is the brains of the operation.  It is typically mounted above the door on the secured side or located in a utility or telecom closet.


How does the system work?

The hardware described above (contact, strike, reader, REX) is installed at the door and wired into a controller.  The controller checks permissions or schedules and manages the door hardware.  The administrator of the system has an user interface to configure system settings, schedules, authorized people, and view information about current and historical system state.


What happens if a card is lost or stolen?

If a card or fob is lost, stolen or broken, the system administrator can disable the card through the management software.  The card cannot be used in the system (unless reactivated) and any further attempted use can be alerted to the administrator.


What happens if the power goes out?  Am I locked out?

Systems can be equipped with battery backup for the controllers, readers and door locks to maintain functionality during a power outage.  Otherwise, doors can still be opened from the inside or by traditional manual keys.


Can it be interfaced with other systems?

Yes.  Typical integrations include cameras, intrusion detection, time and attendance, visitor management systems and more.


Do access control systems only work on doors?

No.  Access control systems can be used on gates, garage doors, elevators, parking arms, turnstiles, machines or vehicles and other applications.


Can I still use my mechanical (traditional) keys?

Yes.  Typically customers re-key their buildings after installing an access control system to account for lost or unaccounted for keys.


What are common acronyms or abbreviations?

Mag – short for Magnetic, in reference to “mag stripe” cards that are swiped like a credit card

PACS – Physical Access Control System

Prox – short for Proximity, the most common contactless cards used in access control

REX – Request to exit

These questions are a brief overview of access control systems.  Modern systems are very powerful and flexible and can be designed for your particular need.

For more information view our access control buying guide – Coming soon

Contact us for more information about access control systems.