Access Control: What is it? How does it work? How does it communicate?

Access Control verifies who is allowed to enter and exit while using a FOB or badge.

The purpose of having an access control system is to provide quick, convenient access control to the authorized individuals, while at the same time, restricting access to unauthorized people.

It implements a security and access level order based on personnel function, automates personnel tracking, records and generates reports of access, and much more.

A few advantages of access control:

  • the ability to lock down entire areas quickly at high threat levels
  • take full and orderly control of your site
  • eliminate the need to man all access points
  • archive records for potential future use

The Access Control Server & Badge Server

The Access Control Server (ACS) runs the software. The server is responsible for assigning access and tracking traffic in secure areas. It maintains a database of credential holders and their access levels.

It also communicates with ACS panels to download specific data to each panel for local flash storage. If the panels are equipped with ethernet cards, the communication could be IP based.

The badging server is where authorized personnel’s data is kept. The server will process the data and issue credentials.

Normally, the employee receives a badge with numerous information encoded:
– photo
– name
– organization
– date of issue
– access areas
– expiration date
– restrictions

photo id card

The badging server is networked with the ACS server so that badges can be updated in the ACS database and downloaded to the access panels where the credential holders are allowed to access. This occurs when changes are made to access areas, personnel, access levels, etc.

The Control Panels

The Control Panels provide the gateway between the control points and the ACS server.

From the door side, the Control Panels process the reader data, report the door position (opened or closed), accept a request to exit from the secure side, and order the electric door strike to open or remain closed.

On the server-side, they respond to polls, report intrusion, alarms, credential problems, tamper alarms, and several other notifications as required to make the area safe.

Panels hold user credential data on flash memory in case the communication between the panel and the server is unavailable. Panels will operate on stand-alone until the communication is restored.

The Card Reader

Door hardware is composed of a reader, door position switch, request to exit button, and an electric door strike.

card reader

There are many varieties of readers with different technologies:

– Wiegand format
– Magnetic stripe format
– Biometric decoders

The readers employ a wire winding to produce a magnetic field.

When a card is presented to the reader, the magnetic field produces an electric field in the card winding. It supplies power to the processor in the card, and the data packet containing the user information is transferred to the card reader.

The reader transmits the data to the control panel, which actuates a relay to apply power to the door strike to open (if the user has access) or report an invalid card (if the user does not have access to the area).

It is Important to Understand the Structure of How the Access Control is Implemented and Used.

At M3T, we do our best to explain the functionality of access control to the user and other security needs across the board.

When the customer has a better understanding of how access control functions and the purpose, it gives them a better satisfaction and a feeling of security in their facility.

Aimee Mathin

Account Manager

If you’d like to know more about access control systems and the advantages they can offer you please feel free to contact us at