What is PoE 802.3at?

what is poe 802.3at

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Engineers are bringing revolution to the world by inventing new things every day. Not only new inventions but also work on old technologies and revise them with better versions. For example, we discuss the power over Ethernet. In 2003, we compromised on the power when the 802.3af standard provided us with 15 watts of power. Only low-power devices can get the power.

With time, engineers upgraded this PoE technology. Now, we have PoE 802.3bt that works for most devices. It doesn’t matter if we have high-power or low-power devices. PoE can work with all devices efficiently.

If you want to know how exactly PoE originated, read our article — How PoE was born?

What is the PoE?

Doesn’t it feel like a buzzword? Yes, it does. In actuality, PoE stands for Power over Ethernet. The discussion doesn’t end here because we don’t know how this PoE delivers the power and its benefits. Something like that is essential for us to learn and understand if we want a brief discussion.

PoE technology involves the Ethernet port to deliver power and data connection to the devices. Whether we are at home or need power in the office, PoE can help us. Even our laptops need the power. Being advanced technology, we can use the PoE to enable power for our devices.

For a detailed guide, read — What is PoE?

What are the different standards of PoE?

I have a simple task for you regarding PoE. Go ahead and search for the different standards. Not found? Let me help you understand what precisely the PoE standards are.

Have you ever heard of the Institute of Electrical and Electronics Engineering(IEEE)? Maybe, yes, especially if you have some knowledge regarding electronic devices. IEEE developed different working standards on which PoE works. You can consider it a principle for the working mechanism for the PoE. Here are those PoE standards.

  • 802.3af (Type 1)
  • 802.3at (Type 2)
  • 802.3bt (Type 3)
  • 802.3bt (Type 4)

What is PoE 802.3at?

We have understood that PoE 802.3at is a standard from IEEE on which PoE technology works.

In 2009, IEEE introduced a PoE plus (PoE+) standard, which provided a high power range to the devices. This PoE 802.3 standard is still used for most of our power devices and provides a data connection and power supply.

Here are some worth discussing points about the PoE 802.3at.

Power Supply:

The power output to power the device from the PoE+ is 30.8 Watts. If we highlight the minimum power available to each device, it is 25.5 Watts. It is the power range available when you use an 802.3at switch such as an industrial-managed switch.

Output Voltage:

Output voltage does matter a lot when it comes to connecting with the device. With a range of 50 to 57 volts of output voltage, PoE 802.3at is available out there for you.

Maximum Current:

We measure currents in units of Amperes. Usually, PoE+ offers a maximum current of up to 600 milliamperes.

Ethernet Compatibility:

Different PoE standards have additional Ethernet compatibility. If we talk about PoE+, it offers 10BASE-T, 100BASE-TX, and 1000BASE-T Ethernet compatibility.


The range shows the distance to catch the signals. PoE Plus offers 100 meters of scope like the other standards do.

To increase the range from 100 meters to 800 meters, you can employ extenders such as 1-Port PoE+ Input to 2-Port PoE Output Intelligent PoE Extender.

Ethernet Cable Pairs:

To make the system IEEE 802.3at compatible, you must know which Ethernet port pairs it supports. Usually, four pairs mean four twisted copper wires for the power supply. Meanwhile, two pairs of Ethernet refers to two pairs of twisted copper wires. In the case of PoE+, it works on two pairs and four pairs of Ethernet ports to supply power and data connection.

Ethernet cable type:

There are numerous types of Ethernet ports. For example, Cat 3, 5, or 6, etc. All are functional and differ from others concerning their power supply, data speed, and bandwidth. In IEEE 802.3at, we need a minimum of Cat 5 Ethernet port to enable data supply.

How to make your power devices PoE+ compatible?

Maybe your device is not PoE compatible, mainly if your switch uses PoE plus technology. We have a solution for you to convert the system into PoE Plus. You can use the PoE plus injectors such as 5Gbps Copper Single Port AC Input 802.3at POE+ Injector(30W).

To understand the installation mechanism, you can understand the following steps to make your device PoE compatible.

  • Make sure everything is working fine— PoE plus switch, power device, and PoE+ injector.
  • Connect your PoE plus switch with the injector through the Ethernet port.
  • Link the power device to the injector with the help of a Cat5 Ethernet cable.

Now, you have a connection between the switch, injector, and device. If the link is working fine, you will get the power supply to your device.

What are the applications of the PoE+ standard?

PoE 802.3at involves uses in many applications where there is a need for a low power supply of up to 30 Watts. Here are significant areas in which we use the IEEE 802.3at standard for data and power supply.

PTZ IP cameras:

Have you ever seen PTZ(Pan, tilt, zoom) IP cameras? Maybe yes, primarily if you have attended an event. These cameras allow movement from 180-degree tilt to 360-degree panning motions. These cameras are part of our security systems as well. However, PTZ IP cameras involve the use of PoE+ technology.

Alarm System:

In surveillance, we use an alarm system to keep infringement in the system. These alarm systems require low power; thus, employ IEEE 802.3 standard.

Video IP phones:

Video IP phones usually connect the voice, video, and data over the IP network. They typically use the IEEE 802.3 standard for their high-speed data requirements.

What are the advantages of the PoE+ standard?

PoE+ technology comes into action with several benefits. You might want to implement it into your system to get the best option for your power supply and data connection.

Dual Supply:

When there is Power Over Ethernet technology, no need to worry about high-speed data connection of up to 1 gigabyte and power supply of up to 30 Watts, a single Ethernet port is enough to supply power and data connection.

Easy to install:

There is no need to hire IT, experts. PoE+ switches are easy to plug in and out. In most buildings, you can find built-in systems for PoE installation. So, you don’t have to take much pain regarding the structure of the PoE+ system.

Saves Money:

PoE+ technology cuts down the need for multiple wires. A single Ethernet port is sufficient to get the power and data supply. Moreover, the preinstalled system in buildings saves you money.

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Hi, I'm Mr. Hua, The funder of HoweVision technology, I'v been woking industrial communication equipment for 8 years now, and the purpose of this article is to share with you the knowledge related to industrial communication from a China supplier's perspective.

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