The five major systems of security systems are video surveillance systems, intrusion alarm systems, intercom systems, entrance and exit management systems, and perimeter alarm systems, of which video surveillance systems are among the most important, and the intuitive monitoring of all types of entrances and exits and channels is dependent on Video surveillance system.
What is the composition of the monitoring system and how is the architecture?
In general it consists of the following parts:
1. Front-end camera: The camera needs to be used with the lens. If it is an outdoor camera, it also needs to increase the lightning protection device. It needs to consider signal and power supply lightning protection.
2. Transmission cables: including network cables and power cables. For example, POE power supply can use twisted pair cables directly, but the transmission distance should be controlled within 75 meters.
3. Switch: All cameras need to be controlled within 90 meters, and can be directly connected to the switch. If it is more than 90 meters, it can be connected to the switch using the network jumper + optical transceiver + optical fiber cable, according to the number of front-end cameras. Select the switch with the corresponding number of ports. In general, the switch upload bandwidth needs to be 45% redundant. Generally, the 100Mbps upload can calculate the number of switches that can access several 2M/4M/8M streams according to the code stream. The maximum connection can be obtained in the case of 8M codestream. Into 7.5 cameras, now the switch port generally has a Gigabit / optical port, according to 45% of the redundancy, you can access more cameras.
Bandwidth of the cascade port: The number of IPCAM streams* is the minimum bandwidth of the upload port. Generally, when the IPCAM bandwidth exceeds 60Mbps, it is recommended to use the 1000M cascade port. For example, the bandwidth required by the cameras with 8 or more 8M streams is 8M*8=64Mbps. At this time, it is recommended to use a Gigabit expansion port.
4, optical transmission accessories: including optical modules, optical cables, optical jumpers, pigtails, corresponding interface coupler (such as SC-LC, LC-LC, etc.), optical fiber distribution frame or wiring box.
5. Core switch: Select the appropriate switch according to the front-end access switch and the total bandwidth of the camera data exchange. The following shows how the switch's packet forwarding rate and backplane bandwidth are calculated.
Packet forwarding rate: The packet forwarding rate of a 100M port is 0.1488Mpps/s, and the packet forwarding rate of Gigabit or 10Gigabit is analogous to this. The packet forwarding rate of a camera is about 2.6 Kbps, which fully meets the requirements.
Backplane bandwidth = number of ports * port speed * 2, such as 24-port 100M core switch (including two Gigabit ports) with a bandwidth of (24*100*2+2*1000*2)/1000=8.8Gbps/S.
Packet exchange rate: port number * port speed / 1000 * 1.488Mpps = packet exchange rate, such as 24-port 100M core switch packet exchange rate of 24 * 100/1000 * 1.488 = 3.60Mpps / S, some switches sometimes packet exchange rate If the calculation fails to meet this requirement, it is a non-line-speed switch, which can easily cause delays when performing large-capacity throughput.
6, storage devices: divided into hard disk recorders and centralized storage devices, according to the number of cameras to choose the right device.
7, the decoder: according to the number of displays to select the corresponding number of decoder
8, the number of monitors:
The specific quantity is based on the local technical regulations.
9, other integrated equipment and software: such as security integrated management platform and software, streaming media forwarding server and so on.
Tribasic Lead Sulfate TBLS
Lead Sulfate Tribasic is a white or slightly yellow powder. Slightly sweet and toxic. Density 7.1, melting point 820℃, starts to lose crystal water above 200℃, refractive index 2.1. insoluble in water and organic solvents, soluble in hot ammonium acetate and alkali, as well as nitric acid and hot concentrated hydrochloric acid. It is non-flammable and corrosive, easily absorbs moisture and decomposes when exposed to sunlight in a humid state.