Security monitoring system is an emerging profession that has been paid more and more attention by people. As far as the current development is concerned, the application is more and more popular, and the technology content is getting higher and higher. Almost all high-tech technologies can promote its development, especially the advent of the information age, which provides opportunities for the development of this profession. However, as far as the monitoring industry is concerned, the system composition has not been clearly divided, which makes it very inconvenient to communicate between the engineering business and the user when it comes to the security monitoring system.
For the security monitoring system, according to the different functions of each part of the system, we divide the entire security monitoring system into seven layers: presentation layer, control layer, processing layer, transmission layer, execution layer, support layer, and acquisition layer. Of course, due to the increasing integration of devices, for some systems, some devices may exist in the system as multiple layers at the same time.
Security monitoring system
1. Presentation layer
Presentation layer can be felt with our intuitive experience, which shows the quality of the entire security monitoring system. Monitoring video walls, monitors, high-pitched alarm horns, automatic alarm call connection, etc. belong to this layer.
2. Control layer
The control layer is the core of the entire security monitoring system, and it is the clearest manifestation of the technological level of the system. Usually we have two control methods: analog control and digital control. Analog control is an early control method, and its console is usually composed of a controller or an analog control matrix, which is suitable for small local security monitoring systems. This control method has low cost and low failure rate. But for medium and large security monitoring systems, this method appears to be complicated to operate without any price advantage. At this time, our more sensible choice should be digital control. Digital control is to use an industrial computer as the control core of the monitoring system. It turns complex analog control operations into simple mouse click operations, reduces the huge analog controller stack into an industrial computer, and changes the complex and huge number of control cables to a serial telephone line. It turns medium and long-distance monitoring into a reality and provides the possibility for Internet remote monitoring. However, digital control is not so perfect. The price of the control host is very expensive; the module is always wasted; the system risks collapsing across the board; the control is lagging behind, and other problems still exist.
3. Processing layer
The processing layer may be called the audio and video processing layer. It distributes, amplifies, and divides the audio and video signals sent by the transmission layer, and organically connects the presentation layer and the control layer. Audio and video splitters, audio and video amplifiers, video splitters, audio and video switchers and other equipment belong to this layer.
4. Transmission layer
The transmission layer is equivalent to the blood of the security monitoring system. In small security monitoring systems, our most common transmission layer equipment is video cables and audio cables. For medium and long-distance monitoring systems, we often use radio frequency cables and microwaves. For remote monitoring, we usually use the Internet, a cheap carrier. It is worth mentioning that the newly emerging transmission layer medium is network cable/optical fiber. Most people have a misunderstanding in digital security monitoring: they think that the digitally controlled security monitoring system used by the control layer is a digital security monitoring system, but it is not. The transmission medium of pure digital security monitoring system must be network cable or optical fiber. When the signal comes out of the acquisition layer, it has been modulated into a digital signal. The digital signal runs on the current mature network and theoretically has no attenuation. This guarantees the lossless display of the remote monitoring image, which is impossible for analog transmission. Of course, high-performance returns also require high-cost investment, which is one of the most important reasons why pure digital security monitoring systems cannot be popularized.
5. Execution layer
The execution layer is the command object of our control instructions. At some point, it is completely separated from the support and acquisition layer we will later talk about. We think that the controlled object is the execution layer device such as pan-tilt, lens, decoder, ball and so on.
6. Support layer
As the name implies, the support layer is used to support the back-end equipment, protect and support the acquisition layer and execution layer equipment. It includes holder, protective cover and other auxiliary equipment.
7. Acquisition layer
The acquisition layer is a key factor in the quality of the entire security monitoring system, and it is also the place where the system cost is the largest. It includes lenses, cameras, alarm sensors and so on.