+351 289 860 320 (*) geral@tecnicontrol.pt


Access Control

Set of subsystems that allow making the management of a building, controlling its users and may restrict the access to certain rooms/sites and to register their movements.

The basic objective of an Access Control System is extremely simple: control who may access at any given time to a certain place.

Often organizations have the need to know who tried to enter a given site using a valid access or if there was an attempt of unauthorized access or, even if authorized, made it out of service hours.

With the use of integrated systems using a unique identifier, an authenticated user can access within the organization, be allowed to access to his car, open all doors to reach his accommodation, including this one, make payments, identify himself to the home automation system if in a residential/tourist resort, and even see automatically debited to his account any costs of restoration, Golf, etc.

The final objective aims to be the overall management of the buildings in which concerns to the movement of people and eventually cars.

Access Control Technologies

Magnetic stripe

Uses magnetic stripe cards, however, is unsafe because the magnetic stripe is affected by magnetic fields, which means that sometimes the recorded data is corrupted, and easily copied and therefore we do not dwell on in his description.


Uses cards that have printed barcodes and is also unsafe because they are easily copied, so we do not dwell on in his description.

Chip / Integrated Circuit (Chipcard)

Use cards that contain an integrated circuit (chip) inserted, which is connected to metal contact points, which are accessible to allow an appropriate reader can read data stored in the chip.

It’s a safe technology because it doesn’t allow copying the data stored in the integrated circuit and has been a large increase in credit and bank debt cards, however, their use in access control systems did not meet great success mainly due to the increasing lower of the prices of the proximity technology systems.

There are various types of integrated circuits (chips) embedded in plastic cards, which differ primarily in the capacity of its memory data storage.

Access to data of each chip in each card is made by inserting a PIN code, however, if more than three (3) failed attempts is made, a fuse blows and the chip is permanently incapacitated, thereby avoiding fraud attempts.


Use devices (usually keychain) having an integrated circuit (chip) embedded in a metallic capsule with the appearance of a large clock battery, hence they are usually designated on the market for “iButtom”, which in contact with the reader allow reading the data recorded in the chip.

It’s a safe technology because it doesn’t allow for copying the data recorded on the chip, however, their use in access control systems did not meet great success mainly due to its high cost.

The number recorded in the chip of each device is unique and has been recorded at the factory, avoiding duplication and fraud attempts.

Proximity (Contactless)

Use devices (usually cards or key ring) having an integrated circuit (chip) embedded, which allows the reading of data recorded in it by approaching to an appropriate reader, hence its name – this technology has replaced all of the technologies described above (magnetic stripe, barcode, chip and contact) with the following advantages:

  • Ease of reading – The reading can be performed without removing the ID device from the wallet (depends on the extent of the antenna of the reader)
  • Versatility – Existence of identifiers in various formats: card, key ring, etc.
  • May not be copied

How it works?

There are several types of proximity chips from several manufacturers.

The most common in the market is the one that works on a frequency of 125 KHz.

It consists basically of three parts: the chip, the antenna and the encapsulation.

The principle of operation is via radio frequency (RF) antennas; one of them is the proximity reader and the other is the own identification device (card, key ring, etc.).

As the identification device has no battery, let’s understand how it can overcome its need for electrical power supply for its operation:

The antenna of the reader emits a constant low power frequency, when the identification device is detected in an area close to the reader, ranging from 5 cm to 90 cm according to the type of reader, the identification device antenna receives the radio frequency wave signals of the reader and, through its internal circuitry, starts the process of storing energy to work.

When it achieve a given load, the internal circuitry of the identification device transmits to the reader the number stored in its chip. In practice, all this occurs during the process of bringing the ID device to the reader, all very fast and imperceptible to the user.

The number recorded in the chip of each device is unique and has been recorded at the factory, avoiding duplication and fraud attempts.


It’s a technology of security based on the recognition of a physical characteristic of individuals and non-transferable, such as the fingerprint.

Biometrics is an automated human recognition, based on physical and behavioural characteristics of people. It’s the same system as the human brain uses to recognize and distinguish one person from another.

A system that recognizes a person based on “who” the person is, no matter “what the person carries” or “what the person knows”.

Things a person can carry, as keys and ID cards, can get lost, be subject to theft and/or duplication, “things” that a person knows, such as passwords and codes can be forgotten, stolen and/or duplicated.

Instead, biometrics is fixed on “who” the person is, based on an immutable human trait that can not be lost, forgotten, stolen or duplicated.

How it works?


In theory, the process of biometric analysis is quite simple.

When the scanner is triggered, its principal function is to obtain a crisp, high resolution image of the object under study: fingerprints, hand geometry, iris, retina or facial expressions.

The next step is to put the captured image to the provision of biometric software, which analyzes and extracts the most relevant features of the figure. In a picture of the hand, for example, what matters are the lines that form the fingerprint/palm print.

Since the image was extracted, the last step consists in comparing the image obtained with the one recorded in the database. This verification is done with the aid of several algorithms, each working differently.

Types of Biometrics


  • Veins of hands – despite having been discovered recently, this feature is very reliable for the recognition of people because, besides being immutable, the counterfeiting of such information is almost impossible. Moreover, the cost to obtain images for identification is relatively low;
  • Fingerprint – It’s the most common form of identification. Besides being the fastest method, it also requires lower-cost resources;
  • Face Recognition – One of the methods for identifying less advantageous. The low reliability combined with the high cost of reading resources, recognition and research of this type of biometric method makes it one of the least used for real-time systems;
  • Iris – Although it requires costly equipment for its analysis, the iris is a very reliable characteristic to identify people, it’s unchanging over the years and almost impossible to be cloned;
  • Retina – The identification through the retina is already widely used in high security systems. It’s totally reliable and the retina is also unchangeable. The problems is the inconvenience in obtaining a retinal image and the high financial cost required;
  • Hand Geometry – Less reliable than fingerprint, the recognition of the hand geometry faces problems regarding the correct positioning of the hand on the scanner bed, not to mention with the rings and accessories that many people use.

General access control systems topologies

There are basically three types of access control systems:

  • On-Line – In networking, RS485 or TCP/IP and managed by a central system, with these systems one can “follow” a user within the organization, the system tells us who is at any given moment in a certain place;
  • Off-Line – Self-contained, with no central management and limited in the number of users;
  • Stand-Alone – With user management software, ability to group users to access groups, controlling for schedules and periods. The information on the granted/denied accesses is maintained in the controller, which can later be collected for future analysis if needed.

Types of equipment associated


  • Devices that can make the decision on access of a user
  • Can be equipped with event log

Reading terminals

  • Devices that only read the user ID

Controlled devices

Are devices that allow access/denial to the controlled premises by its opening/closing and that can be driven directly by the system when running in On-Line mode, or by the ID device when working in Off-Line mode or in Stand-Alone mode:

  • Locks – For door control;
  • Barriers – To control cars;
  • Turnstiles – To manage people;
  • Magneto retainers – Magnetic devices for opening/closing accesses;
  • Electric locks/ /Electrical foreheads – To control doors and gates, are the most common devices, along with locks.