The original chat with you in the era of network monitoring, how to solve the problem of soft failure? The main problem is the cable part, as well as the troubleshooting and testing of some soft problems in the switch system, such as Caton, missing images, etc. The previous time mentioned POE power supply switch, a lot of friends have not exhausted, choose a cost-effective POE switch, that is, to solve the problem of power supply, and can meet the bandwidth problem, is not a good deal, haha.
Now let's talk about how many cameras can be supplied by a POE switch to meet the needs of the security monitoring system.
In the field of security, monitoring as one of the most important parts, wiring and power supply has become an essential part. Traditional monitoring and wiring power supply has been a problem in the industry. In the period of IP video monitoring, network infrastructure support is the key, and power supply is also the most critical part.
In the past, cameras were supplied locally, but since the introduction of PoE, the common form is Ethernet powered IP cameras. PoE, Power Over Ethernet, is the abbreviation of active Ethernet power supply. It refers to the transmission of data signals based on the existing Ethernet Cat.5 wiring infrastructure without any changes, and also for some IP based terminals (such as IP intercom phone, WiFi wireless LAN access point AP, network camera, etc.). Class equipment provides DC power supply technology.
PoE is a difficult problem to solve the power supply wiring. At present, if it is a new monitoring project implemented with the infrastructure, the use of PoE power supply is still relatively small, and the use of PoE power supply in large projects is relatively small. On the contrary, in some civilian, suit market, small projects, PoE applications are very common.
In fact, a PoE switch can supply power to many cameras at the same time. It should consider two aspects: the power supply standard of the PoE switch and the total power supply of the PoE switch.
The power supply of the PoE switch can be understood as the power supply of the single port of the PoE switch. The popular PoE switches in the market have two standards, IEEE802.3af and IEEE802.3at. The IEEE802.3af standard defines a power supply of 15.4W, and the IEEE802.3at standard defines a power supply of up to 30W. Because of the different power supply standards, the power supply of the single port is different. For example, the camera power is 9W, using the AF standard PoE switch; if the camera power is 20W, the AF standard PoE switch is required. If the camera power is above 30W, a special PoE power supply module is needed.
Generally speaking, a PoE switch supporting both AF and at power supply standards is adaptable to its power supply. For example, it is connected to the 5W device, then provide 5W power; if connected to the 20W device, then provide 20W power.
The total power of PoE switches is a very important index, directly related to how many cameras can be brought. For a PoE switch with a power supply of 400W and a 24 port, the total power of the PoE switch is about 370W after eliminating the loss.
Under the IEEE802.3af standard, it can supply 24 ports (370/15.4=24), that is, it can supply 24 cameras at the same time, that is, full load power supply. But if it is calculated according to the IEEE802.3at standard single port maximum power supply 30W, at the same time, it can only supply 12 ports at most (370/30=12).
In actual use, the maximum power consumption of many ordinary network cameras is low, basically no more than 15W. If each PoE port is in accordance with the maximum power (such as 30W) to reserve power power, the power of some ports will appear to be not finished, while some ports can not reach the power rate. For example, some PoE switches support dynamic power allocation, which can avoid this situation. When a PoE switch is selected, it depends on whether the switch supports dynamic power allocation so that each port only allocates the actual power to use, so that the power supply of the PoE switch can be more efficiently utilized.
The switch which supports dynamic power allocation can make the power supply efficiency the highest.
First to understand the maximum power consumption of the power supply device, and then use the total power of the PoE switch to eliminate the maximum power consumption, can be able to get a PoE switch power supply to the number of devices.
POE switch also has a fake? Look at this, you learn more about it, too.
Continuous learning of the POE power supply products! To do marketing is to do yourself! POE power supply manufacturer's voice!