Classification of access control systems

The access control system can be divided into the following three categories according to the access identification method:
1. Password recognition: Incoming and outgoing rights are recognized by verifying that the entered password is correct.
These products are divided into two categories: one is a common type, and the other is an out-of-order keyboard type (the numbers on the keyboard are not fixed and change automatically from time to time).
normal type:
Advantages: easy to operate, no need to carry cards; low cost.
Disadvantages: At the same time can only accommodate three sets of passwords, easy to leak, poor security; no access records; only one-way control.
Disorder keyboard type (numbers on the keyboard are not fixed and change from time to time):
Advantages: easy to operate, no need to carry the card, slightly higher safety factor Disadvantages: the password is easy to leak, the security is still not high; no access records; only one-way control. high cost.
2. Card identification: Through the card reader or reader card plus password to identify the access permissions, according to the card type is divided into:
Magnetic card advantages: lower cost; one person one card (+ password), security, can be connected to the computer, there is a record of open the door Disadvantages: card, equipment, wear, short life; the card is easy to copy; not easy to control. The card information is easily lost due to external magnetic fields, rendering the card useless.
Advantages of RF card: Cards, equipment without contact, convenient and safe to open the door, long service life, theoretical data for at least ten years, high security, can be connected to the computer, and open records; it can realize bidirectional control. Cards are difficult to reproduce. Disadvantages: Higher costs. 3. Portrait recognition: Identification of entry and exit by means of inspector biometrics. Fingerprint type, iris type, face recognition type.
Advantages: Excellent security from the point of view of identification; no need to carry cards Disadvantages: High cost. The recognition rate is not high, the environmental requirements are high, and the user is highly demanded (for example, the fingerprint cannot be scratched, the eye cannot be swollen and bleeding, the face cannot be injured, or the number of beards), and the use is inconvenient (such as iris type and face recognition. Type, installation height position is certain, but the user's height is different)
It is worth noting that most people think that the biometric access control system is very safe. In fact, this is a misunderstanding. The security of the access control system is not only the security of the identification method, but also the security of the control system, the security of the software system, and the security of the communication system. Power system security The entire system is a whole, which is not closed, and the entire system is not secure. For example, some fingerprint access control systems, whose controllers and fingerprint readers are integrated, shall be installed outdoors when installed. In this way, the line that controls the lock switch is exposed outdoors, and is easily opened by people.
The access control system can be divided into the following two categories according to the design principle:
1. Controller comes with card reader (identifier)
The drawback of this design is that the controller must be installed outside the door. Therefore, some control lines must be exposed outside the door so that pedestrians can easily open the door without a card or password.
2. This type of system controller, in which a controller and a reader (identifier) ​​are separated, is installed indoors, and only the reader input line is exposed outdoors, and all other control lines are indoors, and the reader transmits a digital signal. Therefore, no one can enter the door without a valid card or password.
This type of system should be the user's first choice.
The access control system can be divided into the following two types according to the communication method with the microcomputer:
1. Stand-alone products of this type are the most common and are suitable for use with small systems or installation locations. RS485 communication is usually used. Its advantages are low investment and dedicated communication lines. The disadvantage is that once installed, the location of the management center cannot be easily replaced, and network control and off-site control are difficult to achieve.
2. The technical content of such network-type products is high, but it is rare at present, and only a few companies have formed products. Its communication method uses the commonly used TCP/IP protocol of the network. The advantage of this type of system is that the controller and the management center transmit data through the LAN. The location of the management center can be changed at any time. It is easy to implement network control or remote control without rewiring.
Suitable for use in large systems or dispersed locations. The disadvantage of this type of system is that the stability of the communication part of the system depends on the stability of the local area network.