Introduction to Access Control Works

How Door Access Control Systems Work to Increase Security

Door Access Control System
Door Access Control System

It is important to understand how access control works and how it can increase your safety and security. A door access control system is an important part of an organization’s overall security. It ensures that only authorized individuals can enter specific areas of a building. The system performs four essential functions:

  1. Identifies who is allowed to enter
  2. Determines which doors they can access
  3. Defines when access is permitted
  4. Maintains records of who enters and exits

This article describes how access control systems work.

Main Components of an Access Control System

Components of the Access Control System
Components of the Access Control System

An access control system typically includes four primary components:

  • Door Readers – A door reader is used at each door that requires controlled entry. It reads a user’s credentials when they attempt to enter. The door reader determines which types of credentials you can use. The least expensive door readers may read only a PIN code (the least secure) or only RFID Credentials. More expensive door readers can read multiple types of credentials besides RFID cards, such as mobile credentials from smartphones or biometric identifiers such as fingerprints or facial recognition. The door reader is the first line of defense against intrusion. So it’s important to consider what type of credential your organization would like to use before selecting the rest of the system.
  • Controllers – The controller can be a separate device that supports several door readers, or it can be embedded into each door reader. It has a small computer that compares the credential ID obtained from the door reader with the authorized user list. If the credential is approved, the controller unlocks the door.
  • Access Control Management Software – Software used to register users, assign credentials, define access permissions, and track entry and exit activity. Many door access control systems include management software. It’s important to consider the software functionality of the access control system, as you may need additional capabilities. For example, some advanced door access management software solutions offer more capabilities, including elevator control and integration with IP Camera Systems.
  • Credentials – As I mentioned, the door reader will determine what credential you can use, so it’s important to consider the type of credential you would like before selecting the door reader. The credential provides the identification code that authorized individuals use to gain entry. These can include RFID cards, mobile credentials stored on smartphones, or biometric identifiers.

Here’s a Review of the Types of Credentials

Access Control Credentials
Access Control Credentials

Common credential types include:

  • RFID Cards or Key Fobs – The most widely used credentials. The card has a small chip that is energized by a radio signal from the door reader. When it is placed close to the door reader, it automatically transfers its number to the door reader.
  • Mobile Credentials – Smartphone-based identification using Bluetooth, NFC, or Wi-Fi. When your smartphone is placed near the door reader, it automatically transmits your identification number to the reader.
  • Biometric Credentials – Identification based on physical characteristics such as fingerprints, facial recognition, or finger-vein scanning. These offer the highest level of security because you can’t lose or give your card or smartphone to someone else to gain entry.

How the System Works

How Access Control Works
How Access Control Works

Security administrators register users and assign credentials through the management software. Once the hardware is installed, each person who will be allowed to enter is entered into the management database. The person in charge of registering personnel will also enter information about each person, which door they can use, and when they can enter that door.

Once all people are registered, the management software will send the list of IDs to all controllers. When a person presents their credential to a door reader, it sends the credential ID to the controller. The controller checks the authorization database and determines whether access should be granted. If approved, the door unlocks, and the event is recorded.

Summary of How Access Control Works

Door access control systems improve organizational safety by controlling entry, monitoring activity, and maintaining detailed access records. By combining readers, controllers, software, and credentials, these systems provide a reliable and flexible way to protect people, facilities, and assets.

If you would like to learn more, see our video, How Access Control Works.


If you would like help selecting your access control system, please get in touch with us at 914-944-3425, email us at dennis@kintronics.com, or use our contact form.