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Is the Maximum Poe Power Supply Distance Only 100 Meters?

Jun. 17, 2020

PoE suppliers share this article for you.

PoE power supply can save a lot of trouble, and we all know the advantages of PoE switches in the wiring of security monitoring systems, and know the key points in the selection of PoE switches. In fact, many people are more concerned about the maximum power supply distance of PoE switches. Because the farther the power supply distance, the lower the unit cost. So, is the maximum power supply distance of Industrial PoE Switch only 100 meters? Let's take a look below.

PoE power supply switch

Long-distance transmission over 100 meters must exceed Category 5 and above, and it is an 8-core network cable. At the same time, the switch is powered by 8 cores, and the camera must also be powered by 8 cores. The key point is that the PoE switch device supports the network extension mode. When it is turned on, the data transmission and power supply distance of the corresponding port can be up to 100 meters or even 150 meters when using the super five and Internet cables.

Industrial Poe Switch

Industrial Poe Switch

Solve the problem of long-distance transmission, whether the PoE switch is stuck is also concerned. Take a 100M switch as an example:

The bandwidth of the 100M switch is 100M, and the actual utilization rate is about 60%, which is 60M. Calculated with H.265 200W, a single camera code stream, the main code stream 2M-3M, sub-stream 0.5M-1M, according to about 3M calculation.

Theoretically, 100 100M switches can be connected to 20. Of course, this popular calculation method also takes into account parameters such as the upstream port of the switch, bandwidth of the backplane, and packet forwarding rate.

The end connected to the camera is the access layer. Generally, 100 MB is enough, because the camera is basically 100 MB. Gigabit switches are also very cheap now. Once more cameras are connected, try Gigabit access as much as possible, because this will involve upstream ports and backplane bandwidth.

Take a 24-port switch as an example:

24 100M PoE power supply ports, the upstream port of the switch is 2 Gigabit electrical ports and 2 Gigabit optical ports (optical multiplexing), 10/100/1000Mbps adaptive, backplane bandwidth 8.8Gbps.

Connected to 24 200W, the camera code stream is 3Mbps, 24 cameras is 24*3=72Mbps. In other words, the upload port of the access layer switch must meet the transmission rate of 72Mbp/s. Taking into account the actual 50% utilization rate, the switch needs a 1000M upload port. This is satisfactory.

Backplane bandwidth:

24-port switch, 2-gigabit ports

(24*100M*2+1000*2*2)/1000=8.8Gbps can be satisfied.

Since the PoE switch is so easy to use, can it catch the ball machine?

The maximum power of a single-port PoE does not exceed 30W. In principle, the power of the connected dome camera can be accessed without exceeding power. But there are two types of PoE switches, one is about 15W, and the other is 30W (PoE+). When you buy it, you can see it correctly, especially the dome camera. Once infrared is added, it is not easy to say.

Please pay attention to this point, otherwise, it may happen that the infrared light cannot be turned on at night.

Many PoE domes now come with PoE modules, which can be used to supply power to the modules, without the need for switches to supply power. Generally, the power of the dome camera is relatively large, and the single port of the switch cannot be satisfied, but this really needs to pay attention to the power supply distance. Another key point is that the algorithms and tests in the laboratory are very different from the actual situation. The calculated ones are not necessarily usable in practice. The key point: To achieve a power supply of more than 100 meters, you need to cooperate with an 8-core Category 5 network cable and a PoE switch that supports network delay mode.