Alarm linkage means that when an alarm event occurs, related equipment other than the alarm equipment will be triggered to act (such as alarm image review, lighting control, etc.).

After the alarm system is triggered, the alarm control panel sends a signal to the linkage module to turn on the monitoring equipment and searchlights. The monitoring equipment is connected to the AI (analog input) or DI (digital input) channel of the monitoring equipment. Once the monitoring equipment receives the alarm signal, it will output a digital signal to the corresponding digital output channel through software preset or hardware, and link the device switch connected to the DO channel.

The basic realization principle of network alarm system:

The whole system is divided into three parts: client equipment, channel, and alarm center equipment.

1 Client equipment and its functions:

The network equipment at the user end mainly includes: network alarm control panel, motion sensor, door contact, panic button, smoke detector, gas detector, infrared beam, infrared fence, rolling gate clutch sensor and other wireless and wired accessories.

(1) The network alarm control panel has two states: the arm state and the disarm standby state. It can receive the alarm signal sent by the device (through wireless and wired), and the network alarm control panel will automatically send to the alarm center through the public telephone network or other methods in the arm state. The alarm center sends alarm reports, alarm information, and arming and disarming status information.

(2) The PIR motion sensor divides into curtain motion sensor and wide-angle motion sensor. It will find moving objects (with heat radiation) within the detection range and send electronic signals to the alarm control panel. When there is no one in the protection range and the alarm control panel is in the state of arming. Once someone invades illegally, the PIR motion sensor will immediately detect and send an electronic signal to the alarm control panel, and the alarm control panel will send an alarm report to the alarm center to prevent the intrusion of thieves. . The protection range of the curtain motion sensor is a plane, which is generally used to prevent windows and other planes; the wide-angle motion sensor protection area is a space.

(3) The door contact is been installed on the door and window. When the door or window is opened illegally in the armed state, it will cause a change in the state of the door contact and generate an alarm.

(4) Panic button: The panic button is equivalent to a switch, which is used to change the state of the alarm circuit to achieve the purpose of alarm. It is simple, convenient and effective to use. Financial banking systems, shops, supermarkets, enterprises and institutions can quickly get timely assistance from the alarm center when they press the panic button, if a robbery occurs or when a home user has a sick person, or the elderly is in danger.

2 Channels and their functions:

The network alarm system transmits information through the telephone network or other methods. The performance is stable, and the transmission of alarm information is timely and reliable. It is also a relatively mature and mature networking method used today. It mainly plays the role of a medium, connecting the alarm center and the terminal alarm control panel as a whole, so that the alarm center can receive the information reported by the front-end equipment in a timely and accurate manner, and complete the operation of the entire system. There are many transmission and networking methods of networked alarm system: public switched telephone network, GSM wireless network, GPRS wireless network, Internet broadband network, 4G network. The appropriate networking method can be selected according to actual conditions, requirements and market.

3 Network alarm center equipment and its functions:

The core part of the network alarm center is the alarm management software, which determines the basic functions of the center. At the same time, the selection of equipment such as server, network burglar alarm control panel, and burglar alarm accessories also affects the overall performance of the center.