Analysis of relevant elements of RFID technology access control management system

As a new modern security management system, the access control system integrates automatic identification technology and computer control information management measures, and involves many technologies such as electronics, machinery, optics, computer technology, communication technology, and biotechnology. With the development of automatic identification technology, RFID access control management system has become the main component of security system, widely used in industrial automation, commercial automation, transportation control management and many other fields. The access control system based on radio frequency identification technology is the development direction of the future access control system construction.

The personnel access control and attendance management system integrates RFID technology, image recognition technology, network technology, video acquisition technology and other technologies into one, to achieve enterprise employee access control, attendance integration, and digital management. This system has a photo intelligent comparison function, and the system passes images The capture device captures and stores the image of the system when the staff swipes the card and compares it with the system database photo. Successfully eliminating the phenomenon of employee swiping the card provides the most reliable data support for the enterprise to perform reasonable attendance management, and maximizes the intensity of enterprise access security supervision.

RFID access control management system is composed of access control machine (integrated reader, controller), identification card, computer and electromagnetic lock. Generally, there are two types of access control systems. One is that when employees pass the access control system, they simply point the card (RFID electronic tag) they wear on the infrared rays of the access control machine, and the door will automatically open. The other is the RFID UHF long-distance access control system. By installing UHF readers and UHF electronic tags worn by employees, the door can be opened and closed, and the ID card can be read during the entire passage It is fully intelligent and automatic, without the need for workers to operate, saving time. The cost of the second RFID access control management system is relatively high. The choice of these two types depends on the specific needs of the enterprise.

Let's take a closer look at the relevant elements of the RFID access control management system.

Types of access cards

In the system, according to the different permissions, we can roughly divide the access control card into 3 categories, they are time slot card, work group card, privilege card.

Time slot card: as the name suggests, the time slot can be set every day of the week to facilitate the user's management of the people who enter and leave the time slot;

Working group card: the setting provides working day setting and non-working day setting, mainly for enterprise staff to carry out in-out management of working day and non-working day.

Privilege card: not limited by time and level, it can be accessed at any time, suitable for senior management personnel and system maintenance personnel.

Choice of access control electric lock

The access control electric lock is an important part of the RFID access control management system. It is a direct execution device for personnel management. The choice of the electric lock affects the overall stability of the access control system. If you ignore the importance of electric locks, it may also lead to the failure of engineering projects.

At present, the relatively mature access control electric locks on the market are divided into three categories: magnetic locks, cathode locks and electric mortise locks.

Electric mortise locks are more used in glass doors. Depending on whether the glass door has a frame or no frame, it needs to be used with door clips and other installation accessories. In the event of a fault in the access control system, the power supply can be opened to open the door, and it can meet the fire protection when the power is opened Claim. Some electric mortise locks have delay control and door magnetic detection functions. The delay control function supports a certain time after the door is closed and then re-locked. For the glass door whose performance is not good enough to cause the door lock to be difficult to lock, it can be adjusted The delay lock time of the electric mortise lock is improved.

Cathode locks are generally used for single-leaf wooden doors. They are installed on the door side and are used in conjunction with mechanical locks such as ball locks and handle locks. The door can be opened by swiping the card or using the mechanical lock key. It is generally used for room doors with low security requirements. .

Magnetic locks are more used in fire doors and wooden doors. It is not easy to cause performance degradation for a long time. However, the safety of magnetic locks is not as good as that of electric mortise locks. The locked state cannot be guaranteed when a large external force is applied. Magnetic locks with a holding force of 2000N to 4000N are relatively common and are also suitable for most places. Some brands have magnetic locks with a high holding force of more than 5000N. They are suitable for high security requirements for access control, but are not suitable for installing other types of electric Choose the place of the lock.

Problems needing attention in hardware design of RFID access control management system

1. Frequency matching problem

There are two LC circuits in the RFID access control management system, that is, an LC circuit composed of a reader coil and a wiring capacitor, and an LC circuit composed of an electronic tag coil and a link capacitor. In a single-coil system, two LC circuits are required to be tuned to the same resonance frequency. If the resonance frequencies of the reader and the electronic tag do not match, zero modulation will occur, thereby reducing the performance of the system.

2. Optimize the coupling factor

The coupling factor is the coupling between the reader ’s electromagnetic field generating coil and the electronic tag coil. The coupling silver depends on the structural parameters of the system, such as the coil diameter, distance, and coil direction. Optimizing the coupling of silver is beneficial to energy transmission channels and signal transmission channels.