Understanding Access Control

access control

access controlThe term ‘Access Control‘ generally refers to systems that can control, monitor and limit the movement of people, assets or vehicles, in, out and around buildings or sites.

The benefits of using an access control system include preventing loss or damage to capital assets and reducing the risk of personal injury to staff and visitors.

Access control applications range from controlling single entrances to managing large complex sites.

Physical access control system consists of three main components:

Physical Barrier

Physical barriers prevent the entry of unauthorized personnel and have the means of providing access to electricity. This is possible; the door is equipped with an electric locking device, a fence gate, a parking gate or a lift. For doors, magnetic door sensors can be added to monitor door positions, so alarms can raise salaries if doors are left open or opened illegally. Since there is no way to ensure that only one person passes the door when it is opened, strict rules must be in place to prevent authorized users from allowing unauthorized persons to access through the door.

The physical barriers used in access control include doors equipped with electric lock devices, turnstiles, speed gates, elevators, parking gates, sidewalks and vehicle barriers. They all need signals from access controllers before they will allow access.

Sidewalks, gates and vehicle barriers are usually accompanied by a vehicle detector that prevents more than one vehicle from passing each time they open in response to a signal from the controller. Swivel doors and speed doors are designed to allow only one person to pass each time they are activated. The elevator will only stop at a limited level and open their doors if they are allowed to do so by access controllers. However, they can not control how many people come out at that level.

Since a simple door has no way of ensuring that only one person passes when opened, strict rules must be in place that prohibits authorized officers from allowing unauthorized persons to pass the door. If this is not practical, a one-pass system such as a full-height revolving door should be installed. Alternatively, a ‘virtual’ electronic gate or can be fitted to detect how many people pass through the door when opened. This can not prevent them from passing but can raise an alarm to attract the attention of the security guard or activate the camera.

Access Controller and Reader (reader)


Electronic physical barriers are controlled by access controllers combined with some form of reader to identify people with their ‘mandate’. This may be a keypad, card reader or biometric reader. Together, access controllers and readers provide the ability to identify individuals and authorize or deny entry to them.

Access controllers may be ‘stand-alone’ or network for the master (also known as an ‘on-line’) access control system that manages the user database for all PC-based access points. The PC-based software system can update each controller with the details of each individual’s permissions.

PC-based access control systems can offer many additional facilities such as user location, attendance and usage monitoring, visitor management and automatically open the door during emergencies and assigned periods.

By using the software all the information will be integrated into a secure database.

Access Credentials

Norpass3-banner Identity of a person is defined by ‘mandate’, which may use a PIN code, access card, key phrase, or unique human characteristics such as fingerprints. In some cases, a combination of two or more of these credentials can be used to identify the person.

The most common type of credential is the access card (or badge). The types of cards include:

Barcodes – Unique IDs are stored in barcodes on cards similar to the way items are identified for inventory and supermarket checkouts.

Magnetic stripe – unique IDs recorded onto magnetic strips in a manner similar to older bank card details.

RFID (Radio Frequency Identification) – This card stores unique electronic IDs. The card is read by a special RFID reader that communicates with the card using radio frequency (RF) communication. The technology used falls into two main categories, proximity cards (125kHz frequency) and contactless smart cards (frequency 13.56MHz). RFID credentials are also available as key-FOBs or tokens, which are more compact than cards.

Although all RFID systems provide a fairly high level of security compared to the keypads and systems that use a bar code


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