Close this search box.
how door access proximity cards work

How Card Access Work?

Electronic access system offers a better alternative to keys.  Access can be controlled and programmed so that even if an employee lost a card.

Its function as an ID and as ID and authorization is programmable. An employee who leaves the firm can be denied access simply through programming the reader via the computer.

proximity card id badge more secure than keys

Similarly, an employee who lost an ID card need not worry about someone gaining access using his card. The reader can be programmed to deny entry and even raise an alarm should that card be used.

The ability to log and keep track of who accessed a particular door and when it was accessed is a great advantage when it comes to investigating a security breach or theft.

More than that, companies are turning to card access systems to keep track of their employee’s check-in and check-out times.

Coupled with Time and Attendance software, the card access system is fast replacing the punch card system and freeing personnel from the mundane task of entering timesheets and calculating Overtime.

ZK BioTime Time Attendance Software keeps track of staff attendance

Components of a Card Access System

A basic Card Access System comprises the following:

  • Controller – the brain of the system that checks if the data presented by the Reader is valid and whether access should be granted
  • Reader – the interface at the door that reads either your Card, PIN or Fingerprint
  • Electronic Locks – used to lock the doors

Standalone Reader Controllers

A controller is the brain of the system and can operate independently of any computer. Seen another way, it is a dedicated-task computer with its operating system and software. It communicates with the reader, compares the data read by the reader with the information stored at its memory, check its programming setting and output data to the lockset – to either lock or unlock the door, granting or denying access.

The T15EM Card/PIN Reader is an example of a standalone reader controller. That is, the reader and the controller are not separated but one single unit. Such units are economical and very suitable for single door access control applications where you only need to control a single door – namely the front door.

Without external software, all programming such as adding and deletion of cards is accomplished using the keys. Each device comes with a user manual and key code for making configuration changes.

T15EM-W standalone proximity card reader good for single door operation

However, if you want to continuously monitor who came in or out, or if you need regular reports done, standalone readers would not be appropriate as most of these units does not interface to a computer. It is designed to be completely standalone and any programming of new cards or deletion of cards is done via its keypad.

Networked Controllers

Unlike standalone reader controllers where reader and controller are combined in one single PCB board, networked controllers are separate and are normally housed in their metal housing complete with power supply and backup batteries.

The ZKTeco InBio Controller shown here can control 2 doors and support up to 4 readers.

ZKTeco InBio Pro Series multi-door access controller

Network controllers can support up to 16 readers and are often placed in some central location. Where required, network controllers can be linked and connected to a computer and information is shared. A typical application would be companies that may be housed over several floors or a large area and there are many entry and exit points.

Variety of Readers

The alarm System comprises the main panel, keypads, detectors and sensors, and Siren. The main panel is normally located in the utility, store or sometimes under the staircase inside the house. It comes complete with a 7AH battery that keeps it working for up to 2 hours in the event of a power failure.

Wireless Alarm Panel such as the AJAX Hub may sit on a table or mounted on the wall in the open rather than hidden.


Magnetic stripe card readers used to be popular (it is still being used – think of your ATM Card and Credit Cards) though it is fast being replaced by proximity cards. Behind the face of the card is a magnetic strip that allows data to be stored in magnetic fields. Unfortunately, the data can be distorted when the card is subjected to a strong magnetic field or scratches, wear and tear over time.

The cost of proximity cards has drastically reduced over the years, making it the most attractive alternative. With a proximity card, there is no need to swipe the card, hence no wear and tear All that is needed is to flash the card at the reader and the data can be read.

What is gaining ground is the use of biometrics, particularly fingerprints. Biometric readers can read and recognize the fingerprint pattern, increasing the security of the premises. Unlike the card system, it is not possible to pass your fingerprints to someone else. And with the newer batch of fingerprint biometric readers, it can differentiate “live” fingerprints from “dead ” fingerprints.

How Proximity Work

Convenience is desirable and what is easier than approaching a door, opening it and walking in, just as if it were unlocked? With proximity cards, such ease of ingress can be achieved without compromising security. A credit card-sized card can be kept in a wallet, briefcase or purse and when a person walks within three feet of a door, a reader will recognize the card and unlock the door.

Embedded in every proximity card is a special circuitry where its ID number is encoded and an antenna that is used to transmit data using radiofrequency.

There are two types of proximity cards: active or passive. Active proximity cards are typically larger and thicker and contain a battery that powers the embedded circuitry. Passive cards do not have their power source. It draws its power from the reader when it comes within its proximity.

Active cards are typically used for applications where the reader must read the card from a longer distance such as cars entering a car park. Passive cards are typically used for access in and out of offices and buildings.

Proximity readers use an antenna that transmits RF, usually low-frequency RF. When an access card enters the RF field, it transmits a signal back to the reader, which then decodes the signal and grants or denies access.

How Fingerprint Biometrics Work

Fingerprints are unique and no two persons have a similar fingerprint. For that matter, no two fingers have similar prints.

A fingerprint scanner system has two basic jobs — it needs to get an image of your finger, and it needs to determine whether the pattern of ridges and valleys in this image matches the pattern of ridges and valleys in pre-scanned images.

There are several different ways to get an image of somebody’s finger. The most common methods today are optical scanning. The heart of an optical scanner is a charge-coupled device (CCD), the same light sensor system used in cameras. A CCD is an array of light-sensitive diodes which generate an electrical signal in response to light.

The scanning process starts when you place your finger on a glass plate, and a CCD camera takes a picture. The scanner has its light source to illuminate the ridges of the finger. The CCD system generates an image is released.

Face and Palm Recognition the In-Thing

With technological advancement, Face and Palm Recognition is fast replacing fingerprints. Face Recognition readers can read and recognise a face from up to 5 meters and can even identify multiple people streaming in, making face recognition the preferred choice. This is particularly useful for gantry and flap barriers placed at lobbies and building entrances.

face recognition readers for turnstiles chosen for its speed, convenience and accuracy

Related Articles

What is wrong with mechanical locks?
Lock bumping is a lock picking technique for opening...
Read More
How To Choose Multi-Door Access
Selecting and deploying a multi-door system is a business-critical...
Read More
How To Choose A Standalone Door Access
It is often tempting to pick the cheapest reader when...
Read More

Protecting Singapore's offices and homes since 2006

Verified by MonsterInsights