Power and data can be delivered simultaneously over Ethernet connections, thanks to a ground-breaking technology called Power over Ethernet (PoE) voir aussi:....... This approach greatly lowers expenses while streamlining network equipment installation and cabling. At the moment, IEEE 802.3af (PoE), IEEE La norme 802.3at (PoE+), and IEEE 802.3bt (PoE++) are the three primary power supply specifications for PoE. Each standard represents a different set of application scenarios and power supply capabilities.

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Cisco offers a range of PoE switches tailored to various needs. Here are four models that stand out:

●  C9200L-24P-4G-E: 24 ports on this Cisco Catalyseur série 9200 device that support Power over Ethernet. It is designed for medium-sized networks that require automation, programmability, and robust security. Four Gigabit Ethernet uplink ports are present.

●   C9200L-48P-4G-E: 48 PoE-capable ports and four Gigabit Ethernet uplink connections. It is also a part of the Catalyst 9200 Series. Its capabilities are similar to the 24-port model, even though it is intended for bigger networks that need greater device connectivity.

●   C9300-24P-A: 24 PoE ports, this Catalyseur série 9300 switch is well-known for its sophisticated security features, scalability, and quick performance. It is ideal for enterprise-level deployments that require advanced features such as software-defined access.

●   C9300L-48P-4G-E: 48 PoE ports and four Gigabit uplink ports on this Catalyseur série 9300 switch. It combines the advanced features of the 9300 Series with the high port density needed for big network systems.

 >>>More PoE Switches.

3 power supply standards for POE switches

With the development of intelligent security, monitoring has changed from visible to understandable, and has been applied in many aspects. The power of monitoring is gradually increasing. Conventional PoE standard switches cannot meet the demand, so three types of PoE switches have appeared 3 Kind of standard:

●  IEEE 802.3af standard: IEEE802.3af power supply power is 15.4W. If the camera power is 10W, you can use an 802.af power supply switch;

●  IEEE 802.3at standard: The power supply is 30W. If the camera power is 20W, a POE switch that supports 802.3at is required;

●  IEEE 802.3bt standard: power supply power is 90w. Since 802.3at and 802.3af are backward compatible, 802.3af-compatible cameras can be powered by 802.3af or 802.3at switches, but 802.3at-compatible cameras can only be powered by 802.3at switches. Although 802.3at power has increased as a result of the IEEE802.3af/at standard, the powered device’s (PD) maximum PoE power consumption of 25.5W is only appropriate for standard cameras. Compared to high-speed domes, cloud desktop all-in-ones, point-of-sale (POS) terminals, LED lighting, etc., IP video phones require a fraction of the electricity.

2018 saw the release of the updated IEEE 802.3bt, often known as PoE++ or 4PPoE, to address the demands of PD equipment for increased power. The new standard may increase the power level to 90W and updated the earlier PoE and PoE+ specifications.

Comparison of three specific performance parameters

(Read Understanding PoE Standards and Wattage for additional information.)

Why is the Power Supply Distance Limited to 100 Meters?

The fact is that the maximum transmission distance of a PoE switch mainly depends on the data transmission distance. When the transmission distance exceeds 100 meters, data delay, packet loss, etc. may occur.

Because the farther the distance, the greater the resistance, the higher the requirements for network cables, and the greater the probability of problems. Therefore, in order to reduce the occurrence of faults, it is recommended to be within 100 meters.

●  The power loss formula, Q=I²Rt, is to minimize the loss of PoE power supply from the PSE power supply end to the PD powered device. The minimum current and minimum resistance are required to achieve the best effect in the entire power supply process.

●  The resistance is controlled by two aspects, the quality and distance of the network cable.

●  Oxygen-free copper network cable has the smallest resistance, 100 meters resistance: 9.5Ω.

The power supply distance, in addition to the quality of the PoE switch itself, has the greatest relationship with the quality of the network cable. Some use some cheap, poor quality network cables, which do not meet the power supply distance requirements. As a result, problems arise in the project, so check again and again. After working on it for a long time, changing to a good network cable solved the problem immediately. Therefore, for POE power supply, it is best to use oxygen-free copper network cables above category 5e to ensure the stability of transmission and power supply.

Conslusion

Understanding the 3 PoE standards is vital for optimizing the deployment of network devices. Each standard is designed to cater to different power requirements and use cases, from basic IP phones and simple network cameras to high-powered devices such as advanced wireless access points and digital signage. Despite their varying power capabilities, all these standards share a common limitation: a maximum transmission distance of 100 meters.

This distance constraint is rooted in the physical and electrical properties of Ethernet cables. Signal attenuation and electrical resistance both rise with distance as power and data are transferred over the connection. The power and data transmission quality drastically deteriorates after 100 meters, resulting in inconsistent performance. Therefore, in order to guarantee reliable and effective network operations, adherence to this distance limit is crucial.

For those looking to invest in high-quality PoE switches, Home» network.com offers a selection of reliable and reasonably priced options. We make sure you have access to the best networking solutions available to suit your needs as a dependable industry partner. We appreciate you reading, and if you’d want to learn more about networking technology, please check out our other articles.

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