November 30, 2023

Basic knowledge of weak current project access control system: a brief introduction to classification, network and access control equipment

ForewordHello everyone, my name is Mr. Lin, what is access control? What types of common access control systems currently exist? What are advantages and disadvantages of each of them? Let's see below! TextAccess control, also known as access control system, channel management system. It is a digital intelligent control system for personnel access control.

The original concept of an access control system has long been present in our lives. For example: every house in our house is equipped with doors and locks, and people in our family are assigned keys. When family members return, they do not need to ring doorbell, they can directly use keys to open door and enter. People from outside come to visit, and people inside house hear sound of a knock on door, knowing that someone is visiting, and ask: "Who is it?" The people outside respond, "I'm ***!" You open door. This is original concept of access control. The Great Wall is largest primitive access control system in ancient China.

With deepening of electronic intelligence in society, access control systems we see now can be divided into: password-based access control system, card-based access control system, and biometric access control system according to input device, medium, and method.

Password Access Control

When password is entered, system determines that password is correct and activates electric lock to open door. Advantages: you only need to remember password, there is no need to carry other media with you. The lowest cost. Disadvantages: slow speed, it usually takes a few seconds to enter password, if there are too many people in and out, you have to queue. If you make a mistake, you need to re-login, which takes longer. Security is poor, people around you easily remember other people's passwords by gestures, and passwords are easy to forget or leak. Trend: There are fewer and fewer cases where password access control is used, and it is used only in cases with low security requirements, low cost and infrequent use. Example: secure.

Card access control system

Based on type of card, it is divided into contact card access control system (magstripe card, bar code card) and contactless card access control system (also called contactless card, RF card). The contact card access control system is used less and less, because contact card is easy to carry, frequency of use is small, and card is easy to damage, it is only used in cases involving bank cards (magnetic stripe). cards), such as: bank VIP channel access control system, unattended ATM access control systemand other areas of local industry are still in use. Contactless IC cards, due to their durability, good economic performance, high reading speed and high security, are main focus of modern access control system. Therefore, at present, many people simply call contactless access control system with IC card an access control system.

Biometric access control system

An access control system that recognizes identities based on differences in a person's biometric data. The most common of these are: fingerprint access control system (fingerprint characteristics are different for everyone), access control system for tools such as palm (the shape of palm bones is different for everyone) iris access control system (everyone’s retina is different due to optical scanning ) ) Access control to portrait recognition system (facial features and poses are different for everyone), etc. The advantages of a biometric access control system: no need to carry cards and other media, less chance of duplication, copying complexity and high security. The disadvantage is: high cost. Since biometric identification requires comparison of many parameters and features, speed of comparison is low, which does not contribute to cases with a large number of personnel. The biological characteristics of human body will change under influence of environment and time, so it is easy to get a rejection rate (it is obvious that this is a person, but his biological characteristics have changed and he is considered not a person), for example: fingerprints are different due to seasons and dry humidity But different, shape of palm and portrait change due to age, iris changes due to eye diseases, etc. Therefore, although biometric access control system is advanced and secure, its scope is limited, it is only applied in a few areas, such as a small number of people, high security requirements, and high cost. operating access control system.

The access control system also has some derivative forms depending on use cases and application objects. For example: a parking management system to control entry and exit of vehicles, a subway access control system to charge subway buses, etc.

How to classify an access control system? How does an access control system work? What are components of an access control system? What is an access control machine?

The access control system is divided into independent access control system and network access control system according to way of communication with computer.

Independent access control system

It cannot communicate with computer, and access control permissions can be set on keyboard ormachine map. There are also some independent access control machines that use an LCD keypad as card authorization.

Parts of an independent access control system:

Independent access control machine (including card swiping and management) + door open button + electric lock + power supply + induction cardSome can also connect an external card reader to realize card swiping when entering and exiting door.

Basic knowledge of weak current project access control system: a brief introduction to classification, network and access control equipment

Independent access control system

The advantage of an independent access control system: price is relatively cheap and can be installed by decorators who don't need computer knowledge. Disadvantage of an independent access control system: security is poor, because relay controlling electric lock is in multifunctional machine, and criminals can short-circuit or destroy independent access control without much professional knowledge. The machine can be used to open a door, and even some strong magnets can attract a relay in an independent access control machine to open an electric lock. Although some manufacturers have made improvements and placed buttons and relays inside power supply, they have not dramatically improved safety factor. Setting card permissions is quite inconvenient if there are several doors in company that require access control, they need to be set and canceled one by one.

Therefore, an independent access control system is suitable for cases where level of security is not high (cases where level of security is not high (prevent gentlemen, but not villains), cost budget is very low, number of doors is limited). small, and there is no need for quick authorization and analysis of access control records.

Internet access control system

The ability to communicate with a computer, set card permissions, and parse and query access control entries using access control management software installed on computer. Even if computer is not turned on, system can also work normally offline. The software can set permissions and parameters, and control entry and exit of each door in real time. Can read attendance reports and so on.

Components of a network access control system:

Access controller + card reader + exit button + communication hub + proximity card + power supply + access control software.

Notes. If you connect two card readers and do not connect door open button, you will be able to swipe your card when entering and exiting door. If it is connected to a password card reader, "card + password" function can be realized to prevent other people from seizing card and unauthorized entry. Higher level of security. The biometric identification device (fingerprint reader, palm device, etc.) with wiegand26 international communication interface output format for card reader can replace card reader and connect with controller to achieve a higher security level of access control system.

According to communication mode of access control controller, it can be divided into an access control systemm to 485 network and a TCP / IP network access control system

Basic knowledge of weak current project access control system: a brief introduction to classification, network and access control equipment

Typical network mode of a 485 access control system

Basic knowledge of weak current project access control system: a brief introduction to classification, network and access control equipment

Typical network diagram of a TCP/IP network access control system

Notes: In addition to RS485 and TCP/IP, there are other bus structure access control systems on market, such as LAN bus, etc. Because there are not many of these products on market, and they have their own advantages and disadvantages, they will not be detailed here.

The advantages of network access control system: system has high security factor, good economic performance, powerful functions and convenient operation. Additional features such as attendance can be obtained by analyzing and managing card swiping record data.

Among them, TCP/IP network access control system has more advanced technology, faster communication speed, wider network range and more stable communication. Because price is slightly higher than 485 network access control system, current popularity is not as good as 485 network access control system, but it will undoubtedly become mainstream of network access control system in near future.

At present, mainstream and trend of access control system is network access control system, which is preferred choice for medium, high, medium and high and medium and low level companies. end users.

What is an access control machine?

The so-called all-in-one access control system is an access control product that combines a card reader and a controller. There are independent types and network types. Compared with network access control system that separates card reader and controller. controller, its cost is lower., but because control part is open, and security level is slightly lower, it is often used for users with one access control point in some companies. The stability and security requirements of users of a high level of access control.

The all-in-one is often equipped with keyboard settings and an LCD display, which can meet appearance needs of some home customers, but since LCD is a vulnerable part, its stability and anti-interference will not be reduced. as well as card reader and controller are separated. Network access control products, imported products (except for some Taiwanese products) generally use card reader and controller separation mode.

Basic knowledge of weak current project access control system: a brief introduction to classification, network and access control equipment

A few common multifunctional machines on market

How an access control system works

We use humans and computers to illustrate intelligent principle of an access control system.

Smart things often consist of following components:

Input devices Output devices Central processing and memory devices Communication devices

Human eyes (receiving visual input), skin (tactile input), ears (audio input), etc. are input devices. Human hands and feet are action output devices. The human brain is central device for processing information and memory. The human mouth and ears are receiving and transmitting devices for communication. People receive information through eyes, skin, ears and other input organs, after analyzing and judging brain and comparing memory, and then make desired movement of arms and legs, and then complete intelligent behavior. Through language communication, a group is formed.

The computer keyboard and mouse are input devices that are analyzed and evaluated by host computer (motherboard CPU, memory and hard disk are used as memory) to make decisions, and then respond and output through speakers, monitors, printers, etc. etc., and complete intellectual behavior. Computers form a computer network through network cards and protocols.

The same applies to access control system. The input device of access control system consists of a card reader and a magnetic button signal. The signal is sent to controller. The electric lock action of equipment realizes process of opening door, and alarm is triggered through alarm. Through 485 TCP / IP communication equipment, protocol is similar to human language, and the network is formed to form an access control group.

Basic knowledge of weak current project access control system: a brief introduction to classification, network and access control equipment

Access control principle

What is an access control controller?

The access control controller is main part of access control system for processing and storing data, as well as heart of access control system.

Regular classification of access controllers

According to communication method between controller and host computer, it is divided into: RS485 network access controller, TCP/IP network access controller

Notes: The RS485 access control network controller usually also has communication mode of RS232 serial port, RS232 serial port and computer for offline communication. In addition, controller's network communication method also has a Lan Longwork fieldbus method, but these communication methods are rarely used and have their own advantages and disadvantages. It is inconvenient for users to replace them with other compatible products in future, so I will not talk about them here.

According to number of doors controlled by each controller, it can be divided into: one-door controller, two-door controller, four-door controller

Notes: There are also 8-door controllers, 16-door controllers, and 32-door controllers on market. The output is very small. Products designed by manufacturer for cost reasons are actually very inconvenient in structure and wiring, and 8 doors are required (16 doors and 32 doors), equipment can only be used within effective communication range, and because too many lines enter host chassis, it is easy to cause interference and become unstable. Therefore, author believes that these products are only conceptual products, and have not yet entered practical link. Some manufacturers release products out of a desire to flaunt their technological leadership. In fact, number of valves controlled by controller does not reflect advanced design of product. Adding inlet and inlet ports to a four-door controller becomes eight. 16 doors and 32 doors are not very complex, but this results to negative consequences for stability, and inconvenience of design has a greater impact.

Depending on number of card readers that can be connected to each door, controller is divided into: single-sided controller and double-sided controller

If you enter a door by swiping a card and exit by pressing a button, controller can only connect to one card reader per door, we call it a one-way controller.

If there is a door, card is swiped when entering door, and card is also swiped when exiting (the door button can also be connected), each controller can be connected to two card readers for each door, one is entry card reader and other - an output card reader, which we call a two-way controller.

Notes: If a two-way controller is connected, then only card reader is connected to input, and card reader to outputis not connected when exiting (the port is free), and door is connected to exit button to open door when exiting. A function equivalent to a one-way controller is also possible.

Here you need to distinguish between concept of "double doors". Some doors can open and open, or they can open in and out. It has nothing to do with classification of access controllers. There is also concept of "double doors". Some doors, such as company's glass gate door, consist of two doors on left and right, but each door is equipped with an electric lock, and two locks are connected in parallel to one of controllers on door relay. Instead of a two-leaf controller, only a single-door controller can control a two-leaf door.

Some customers have asked if two card readers can be connected to one card reader port. Theoretically, this is impossible. Two card readers may interfere with each other and damage card reader and controller. The card read record cannot be distinguished as an input record or an output record. A single card swipe can create two entries. Although there are no major problems when testing connection on desktop, we still recommend that you do not do this in order to avoid problems with damage to equipment in future.

What are most commonly used communication and networking methods for access controllers? What is difference, advantages and disadvantages of RS485 network access controller and TCP/IP network access controller?

Common communication methods for access control controllers: RS232 RS485 TCP/IP

RS232 mode:

means one controller is connected to computer serial port via RS232 serial port communication protocol for point-to-point control.

Some people also refer to RS232 as serial communication.

RS232 communication method, maximum communication distance is 13 meters (communication is stable at this distance), for micro-processing, most stable distance within 3 meters is recommended, so micro-processing controller's standard serial communication line is 3 meters. If it needs to be extended, extend 2 3 5 wires among 9 wires, how to extend, refer to related article "RS232 communication principle, how to increase length of RS232 communication wire?". Although it seems that test above 13 meters can also communicate, but it is unstable and has poor noise immunity, so it is not recommended to do this. A typical desktop computer has 1-2 serial ports (Com1 Com2), which can be expanded to 255 serial ports with a multi-serial card. New laptops usually do not have a serial port, so you need to purchase a USB to serial converter to implement it. For details, see "How do I use a USB to serial converter?"

Each RS232 serial port can only communicate with onehim a controller.

The baud rate (commonly known as baud rate) of RS232 communication method is typically 9600 baud. The micro-tillage controller's baud rate is rated at 9600 baud. The transfer rate is more than a dozen resolutions or records per second. .There are a few more on market. The baud rate of some companies' controllers is 2400 4800 19200 38400. The higher baud rate, higher baud rate, but shorter stable transmission distance and worse anti-jamming ability.

RS485 communication method:

Several controllers via an RS485 communication bus (twisted pair or one of network cables must be used), controllers are connected in series with each other, and one bus is connected to an RS485 converter (hub). to serial port of computer to realize control and communication of one computer (software) with several controllers.

Communication distance:

The theoretical distance between farthest controller and computer is 1200m. Customers are advised to operate it within 800m, and best effect can be controlled within 300m. If distance is too long, you can purchase a repeater (extension cable) 485 (please Purchase it from a professional converter manufacturer.If repeater is located in middle of bus or at beginning, please refer to relevant instructions of manufacturer.) Purchasing The repeater can theoretically be extended up to 3000 meters.

Upload quantity:

This is how many controllers 485 bus can carry, it depends on choice of controller communication chip and 485 converter communication chip. Generally, there are options of 32, 64, 128, and 256. This is a theoretical number. In a real application, depending on site environment , communication distance and other factors, number of loads can not reach index number. Micro Tilling's controllers and converters are rated at 256 units, and in reality, customers are advised to drive each bus within 80 units. If there are hundreds or thousands of controllers, use multi-port cards or 485HUB to solve problem. For details, see "How to build a network when there are hundreds or thousands of controllers in system?" Absolutely forbidden. use 485 passive converters. The cost of 485 source converter is only ten dollars. Although rated load is 32 units, 5 units cannot be transferred in practice, and communication bus length cannot exceed 100 meters. There is no lightning protection and surge protection design, etc. e. Please contact us for details. See "Why is it forbidden to use 485 passive converters?"RS485 communication method must be connected in series through twisted pairs hand in hand, and bifurcation or star connection For more details andRefer to "RS485 Communication Principles and Wiring Precautions" for information.

TCP/IP communication method:

The TCP/IP communication protocol is current universal standard computer network protocol, which has advantages of high transmission speed, international standard, and good compatibility.

The access method of controller is same as that of LAN hub and network card of computer.

Communication distance:

In a small LAN, communication distance can be extended by cascading hubs. The communication distance of each layer can be up to 100 meters, and multiple layers can be cascaded. Moreover, a large local area network can be extended over many kilometers or even across cities using various methods such as fiber optics and wireless, and can also be connected to Internet for thousands of kilometers. Number of downloads:

Theoretically, there are no restrictions, hubs can be cascaded, and there are no problems connecting thousands of controllers to a network.

Link speed:

The communication speed is fast, communication speed of TCP/IP product is ten or even tens of times faster than RS485 RS232 controller. There are over 100 or even hundreds of upload permissions or upload records per second.

Other networking methods:

In addition to basic RS485 TCP/IP communication method, very few companies also use LAN LONGWORK and other bus methods to form a network. These methods are rarely used and have their own advantages and disadvantages. Compatibility between products is poor. , technology is not popular, so I will not present it here.

Most RS485 access controllers have RS232 communication ports, but you usually need to set which communication mode to use with jumpers or switches.

Some brands of controllers integrate RS485 and TCP and are designed using dual communication methods. This design is relatively expensive and impractical, and is mostly common in products of some imported brands.

Comparison of advantages and disadvantages of RS485 controller and TCP controller:

RS485 controller advantages:

The cost is relatively low, and it is a separate network that will not interfere with general network of other devices.

Disadvantages of RS485 controller:

The number of networks is limited, usually within 1000. The more devices, more complex network and higher interference. The range of network is limited, usually within a few hundred meters.

The connection speed is relatively slow. For a system with more than 10,000 people and hundreds of doors, download speed of permits and download records is relatively slow.

Benefits of TCP/IP controllers:

Adopting popular international standard communication protocol, improved performance and performance relativebut are good and it won't be fixed for many years. The number of networks is not limited, and scope of network is wide, it can cross regions or even borders.

The communication speed is fast, and it is suitable for access control systems with more than 10,000 people and hundreds of doors. The connection quality is stable and is not disturbed by outside world. If user already has a network such as a LAN, there is no need to rewire network and use existing network to form a network.

Weaknesses:

The cost will be slightly higher than RS485 controller.

What is a contactless IC card (RF card, inductive IC card)?

Contactless IC card, also known as RF card, induction card, induction IC card.

Among them, we use a read-only card (the card number (ID number) can only be read through card reader, and card number is solidified (cannot be changed), and data cannot be written to card section. This type of contactless cards, we call it ID card for short. EM (chip manufacturer) ID card has absolute share of ID cards and has best value performance, so it is also called EM card or EM ID card.

For contactless IC cards that can be read and written, most products on market use Philips Mifare One chip (some call it M1 for short), so we call it Mifare one card or Mifare card. or M1 card. There are also some cards, such as Ti Logic, which have a very small market share, so I won't present them here.

Mifare One card, among which ISO1443 TYPE A format is most widely used, and is widely used for access control, attendance, consumption and other universal cards. The TYPE B format is used in some cases such as ID cards, subway passes, etc.

ID cards and Mifare cards account for more than 90% of contactless IC cards.

The capacity of a Mifare card is most commonly 1KB (FF) (there are also 4KB which are little used in China and will not be shown here)

A 1KB Mifare One card is usually divided into 16 application areas (0-15 areas), and each area can be encrypted separately for different use cases of card. Each application area has 4 blocks (blocks 0-3) and each block has 16 bytes. 0, even if it is encrypted, its block 0 can still be read, it solidifies and cannot be changed, among them, card serial number is 4 bytes, and Wiegand26 international standard for access control will use 3 of them section as card number.

The serial number of Mifare card identification card (card number) consists of four bytes, FF FF FF FF.

Take third byte FF and convert it to a 3 digit decimal number. For example: 255

Converting first two bytes along with FFFF to decimal is 5 digits. For example, 65535

3 digits and 5 digits are connected together (for example: 25565535), total 8 digits, which is card number of this card, which conforms to international wiegand26 standard.

Family cards are divided into thick cards, thin cards, and odd-shaped cards based on their shape.

Basic knowledge of weak current project access control system: a brief introduction to classification, network and access control equipment

Thick card

Thick card: The price is relatively cheap, durable, and a thicker card is not as convenient as a thin card in a wallet. It is suitable for portable work card. 86mm*54mm*1.8mm

Basic knowledge of weak current project access control system: a brief introduction to classification, network and access control equipment

Thin Map

Thin Card: The same size and thickness as a regular credit card. 86mm * 54mm * 0.76mm

There is also a type of card whose thickness is between a thin card and a thick card, which is more economical than a thin card called a thick card. 86mm*54mm*1.0mm

Special shaped card

Irregularly shaped cards are used to make key chains, as well as watches and buttons.

Based on type of card being read, card reader is divided into ID card reader (EM card reader), Mifare One card reader (M1 card reader, Mifare card reader, IC card reader)

Commonly referred to as contactless IC card reader, RF card reader, inductive IC card reader.

The distance to card reader is usually 2 to 16 cm, and distance to Mifare card is less than to ID card.

Pinpad card reader. Some card readers have not only wiegand26 card number output, but also wiegand26 keyboard output, which is suitable for card and password access control cases.

Output format: wiegand26 keyboard format in Un-buff format.

What is a card reader? What are types of card readers?

General Map Reading Styles:

Regular card reader:

Basic knowledge of weak current project access control system: a brief introduction to classification, network and access control equipment
Basic knowledge of weak current project access control system: a brief introduction to classification, network and access control equipment
Basic knowledge of weak current project access control system: a brief introduction to classification, network and access control equipment

PIN code reader:

Basic knowledge of weak current project access control system: a brief introduction to classification, network and access control equipment
Basic knowledge of weak current project access control system: a brief introduction to classification, network and access control equipment
What is a long range card reader?

Long range card reader means that card reading distance is relatively long, and it is usually used not for access control, but for parking lots.

The long range card reader must communicate with appropriate card. Among them, passive card (there is no battery inside card) and long-range card reader generally have a reading distance of 30-90cm. The active card (the card is relatively large and thick, with a built-in battery that needs to be replaced regularly.) The long-range card reader's card reading distance is 1 -7 meters. Mainly used to pay for logistics expressways, etc.

Some long distance card readers are equipped with an anti-collision mechanism that can simultaneously read multiple cards in reading area (the specific number of cards varies by product), while door-to-door readers usually require, to previous card After card is read, leave swipe area, and second card can only be read if it is close. If first card is still in swipe area, no other cards can be read. The overall reading speed of a card reader without doors is about 0.3-1 second per card.

Types of electric locks that block doors and their characteristics

Commonly used electric locks for access control include: electric mortise locks, magnetic locks, electric locks, electric control locks, etc. (Sorted by penetration of use)

Electric Mortise Lock:

Some people also call it an "anode lock", but it's really just a kind of "anode lock", that is, an electric lock that opens door when there is a power outage. Because according to requirements of fire protection, in event of a fire in building, power supply will be automatically cut off, and electric lock must be opened to facilitate evacuation of personnel, so most electric locks open door when power is turned off.

Basic knowledge of weak current project access control system: a brief introduction to classification, network and access control equipment

Four-wire electric mortise lock

Electric mortise locks are divided into 2-wire electric mortise lock, 4-wire electric mortise lock, 5-wire electric mortise lock and 8-wire electric mortise lock according to wires.

Two-wire electric mortise lock: there are two wires, red and black, red is connected to +12VDC power supply, and black is connected to GND. Disconnect any wire, lock head will retract and door will open. Two-wire electric lock, structure is relatively simple, there is no single-chip microcomputer control circuit, lock body is easy to heat and burn hands, and shock current is relatively large, which belongs to low-end electric mortise lock with a relatively low price.

Four-wire electric mortise lock: there are two wires, red and black, red is connected to +12VDC power supply, and black is connected to GND. There are also two white lines, which are door magnetic signal lines, indicating open and closed state of door. It outputs various switching signals to access control controller to make decisions through door sensor according to current state of door, open or closed. For these functions, door magnetic signal line cannot be connected. The four-wire electric mortise lock uses a single-chip microcomputer controller, which has soft heating, delay control, and door magnetic signal output. It is a widely used electric lock with good economic performance.

Basic knowledge of weak current project access control system: a brief introduction to classification, network and access control equipment

Setting door closing delay on electric lock

The so-called delay control means that there is a dial on lock body that can set delay time for closing door. Usually it can be set to 0 seconds, 2.5 seconds, 5 seconds, 9 seconds. Each manufacturer's lock is split into several files and delay is slightly different.

Please note that this delay is different from door open delay set by access controller and access control software.

The access control controller and access control software sets "door open delay" or "door delay" which is number of seconds after electric lock opens door and closes it automatically.

The built-in electric lock delay is a door closing delay that determines how long after door is in place, lock head will lower and door will close. The general access control system requires that after door is closed in place, lock will lower and door will be closed. Therefore, default electric lock delay is set to 0 seconds. For some doors, floor spring is not suitable and door swings back and forth several times in closed position before door settles. stabilized after a few shakings, and lock head lowered again to close door.

5-wire electric lock:The principle of operation of a 4-wire electric lock is same, but there is an extra pair of opposite door sensor signals. Used in some special cases, but it's problematic in official cases. Engineer Which pair to test with.

The red and black wires are power. There are also three lines COM NO NC, NO and NC form two pairs of signals opposite COM respectively (one set of closed signals, one set of open signals). After door is opened, close signal becomes open signal, and one group of open signals becomes close signal.

8-wire electric mortise lock: The principle is same as 5-wire electric mortise lock. Only in addition to door sensor status output, lock status output is also added. That is, signal is different, whether head of lock sticks out or not.

Electric Mortise Lock: Commonly used for glass doors, wooden doors, etc.

Advantages: Hidden protection, beautiful appearance, good protection, not easy to open and disassemble.

Disadvantage: Difficult to dig a keyhole during installation.

Notes: some glass doors do not have a threshold (that is, door frame is also made of glass), or top of glass door does not have a hemming, so you need to buy accessories forframed glass doors to help with installation. . The cost of components is not low due to low performance. electricity

Magnetic lock: also called an electromagnetic lock. It is an electric lock that uses suction force generated between an electromagnet and an iron block to close door.

A magnetic lock is also a kind of electric lock that opens door when the power is turned off.

Basic knowledge of weak current project access control system: a brief introduction to classification, network and access control equipment

Terminal inside magnetic lock

Some magnetic locks display status of door (magnetic door status). You should carefully monitor terminals. In addition to power terminals, there are three COM NO NC terminals. The functions of these terminals can be determined according to current state of door. Whether it is open or closed, various switch signals are output to access control controller for decision making. For example, functions such as intrusion alarm, access control door that has not been closed for a long time rely on these signals for evaluation. If these functions are not needed, door status signal terminal may not respond.

Magnetic locks are commonly used for wooden doors, fire doors.

Advantages: The performance is relatively stable, and repair rate will be slower than other electric locks. Easy to install, no need to dig a hole for lock, just use wire channel and fix lock body with screws.

Disadvantage: Typically installed on top of sill on outside of door, and due to impact, aesthetics and security are not as good as a hidden electric mortise lock. The price is similar to electric mortise locks and some will be slightly higher.

Due to limited suction power, normal model has a force of 280kg, which can be suddenly pulled by many people at same time or by people with a lot of force. Therefore, magnetic locks are usually used in some cases that do not require high security, such as in office, where gentlemen are not protected from villains. In some security situations such as "prisons", if magnetic locks are used, magnetic locks with a pull force of more than 500 kg will be made to order.

Electric Lock: (Electric Lock) Some people call it "cathode lock", but it's not true, it's just one of models which is a kind of cathode lock. Installed on side of door and must be used with a mechanical lock.

Basic knowledge of weak current project access control system: a brief introduction to classification, network and access control equipment

Pros: Inexpensive. There are two types: power on and power off.

Disadvantages: The shock current is relatively large, which greatly affects stability of system. Since it is installed on side of door, wiring is very inconvenient, because there is a baffle frame in middle of side door, and wires are not convenient to run from top of door through door frame. The lock body needs to be hollowed out and embedded, so it is difficult to install. The door can also be opened via a spherical mechanical lock without swiping a card, which reduces security and ability to request an electronic access control system. The destructive force that can be allowed is limited, and it can be opened with a kick. Basically, I do not recommend that you use this kind of electric lock.

Power lock: Mainly used for community front door, second door of bank savings bank, etc. It can also be opened with handle or key locked inside the door.

Basic knowledge of weak current project access control system: a brief introduction to classification, network and access control equipment

Power lock

Disadvantages: The surge current is large, which greatly affects stability of system, a "click" is heard when door is opened, and noise is relatively large. Installation is inconvenient and professional welding equipment is often required to spot weld it to iron door. Please note during construction, door opening delay cannot be long, it can only be set for 1 second, if time is long, it may cause thermal damage to electric control lock.

In order to overcome these shortcomings, new "silent electric lock" is called "silent lock" for short, and some people call it "motor lock". It's designed. It no longer uses principle of an electromagnet, but drives a small motor to retract lock.

Other electric locks, such as glass door locks, top and bottom suction magnetic locks, and other electric locks, have little use, and some are still being phased out, so I won't present them here.

Types and selection of commonly used door openers for access control

There are two common access control methods:

1 Swipe to enter and swipe to exit. We usually refer to this as "two-way access control" or "two-way card swiping". The advantage of this method is that it has a higher level of security and generally people are not allowed to go outside by accident. there are records that can be requested, and they know who went out and when, which door.

2 Swipe to enter, no need to swipe to exit, just press door open button to open electric lock and exit. We usually call this "one-way access control" or "one-way card swiping". The advantage of this method is that it is convenient and convenient to go out. internal personnel), cost is lower and this method is more popular. For sake of cost efficiency, most of internal office access control doors use this mode.

The "exit button" or "door open button" used in this mode is an integral part of access control equipment.

The principle of exit button is actually similar to that of doorbell button. When you press it, two internal contacts turn on. disabled. Hence, someone in some projects can also directly use doorbell button to make a door button. It's just that doorbell button usually says "bell".

Separation by material: It can be divided into plastic buttons and metal buttons. Plastic buttons are cheap, durable and look less prestigious than metal ones. Metal buttons look expensive, and their service life is not as long as plastic ones, but they can also be used for many years, and even a touchwill be stronger.

Divided by size: It can be divided into 86 buttons of bottom block (the bottom block of our regular wall socket and fluorescent light switch is bottom block of 86) and small buttons (there are many). sizes of small buttons In general, appearance is more beautiful than button 86 of bottom drawer, but it is not as atmospheric and standard as button 86 of bottom drawer).

Related