Comprehensive Guide to Access Control System

March 10, 2016

It is clear that access control systems offer tangible benefits for businesses, such as the prevention of loss or damage to capital assets and the reduced risk of personal injury to staff and visitors. But what is access control system? What are the main elements of access control system? And what impact these elements have on the overall access control system?


Access security system applications range from controlling a single entrance door to managing a large complex site. Physical access control systems comprise three main components: Physical Barrier, Access Controller and Reader, and Credentials. Depending on the cite characteristics, these components can vary and incorporate different technologies.

Therefore, we compiled a comprehensive guide, describing each access control component in detail:


physical barrier

The physical barrier prevents the entry of unauthorised personnel and has a means of granting access electrically. Physical barrier includes doors fitted with an electric locking device, turnstiles, speed gates, lifts, parking gates, bollards and vehicle barriers. They all require a signal from the access controller before they will permit access.

For doors, a magnetic door sensor may be added to monitor the door position, so that an alarm can be raises if the door is left open or opened illegally. Because there is no means of ensuring that only one person passes through a door when it is unlocked, strict rules must be in place to deter authorised users from allowing unauthorised people access through the door.

Bollards, gates and vehicle barriers are usually accompanied by vehicle detectors that prevent more than one vehicle passing through each time they open on in response to the signal from the controller.

Turnstiles and speed gates are designed to allow just one person to pass through each time they are activated.

Lifts will only stop at restricted levels and open their doors if they are permitted to do so by the access controller. However, they can’t control how many people get out on that level.

Because a simple door has no means of ensuring that only one person passes through when it is unlocked, strict rules must be in place forbidding authorised personnel from allowing unauthorised people to pass through the door. Where this is not practical, then a one-pass system such as a full-height turnstile should be fitted. Alternatively, an electronic or ‘virtual’ turnstile can be fitted to detect how many people pass through the door when it is unlocked. It can’t prevent them from passing through but it can raise an alarm to attract the attention of security guards or activate a camera.


access controller and reader

The physical barrier is electronically controlled by an access controller combined with some form of reader to identify people by their 'credentials'. This may be a keypad, a card reader or a biometric reader. Together, the access controller and the reader provide the ability to identify an individual and authorise or deny entry to them.

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

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



The identity of an individual is determined by a ‘credential’, which may be a PIN code, an access card, key fob, or a unique human characteristic such as a fingerprint. In some cases, combinations of two or more of these credentials may be used to identify the person.

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

  • Barcode - a unique ID is stored in a barcode on the card similar to the way goods are identified for stocktaking and supermarket checkouts.
  • Magnetic stripe - A unique ID is recorded onto a magnetic stripe in a similar way to details on older bank cards.
  • RFID (Radio Frequency Identification) – These cards store the unique ID electronically. The cards are read by special RFID readers that communicate with the cards using radio frequency (RF) communications. The technologies used fall into two main categories; proximity cards (125 kHz frequency) and contactless smart cards (13.56MHz frequency). RFID credentials are also available as key-fobs or tokens, which are more compact than cards.

Although all RFID systems provide a reasonably high level of security compared to keypads and systems using bar codes or magnetic stripes, there is a wide choice of security levels, with the price of the card usually reflecting the level of security provided, Smart card systems are particularly secure due to advanced encryption techniques and, in certain products, strict control of encoding and distribution.


What access control systems are you using? Not sure which access control solutions are best for your site? Tweet us at @NortechControl!