The Ethernet LAN (local area network) cable technology known as Power over Ethernet (PoE) enables the electrical current required for each device's operation to be carried over data cables rather than power connections. By doing this, the number of cables needed to install the network is reduced.

In comparison to traditional cabling, this results in reduced costs, fewer downtime, simpler maintenance, and more flexible installation.
In order for PoE to function, the electrical current needs to enter the data cable at the power end and depart at the device's end. This keeps the electrical current separate from the data signal and prevents interference between the two. A part known as an injector allows current to flow into the wire. The device at the other end of the cable will function properly without change if it supports PoE. A part known as a "selector" or "faucet" must be fitted in order to eliminate the current from the cable if the device does not support PoE. The electrical outlet receives the discharge from this "faucet."

The most advanced PoE systems employ fault protection to reduce the likelihood of equipment damage in the case of a breakdown. In the event that a short circuit or excessive current is detected, this feature turns off the power supply.

What is a PoE made of?
1- The Power Injector

It is in charge of providing the complete kit with the energy it needs. The Ethernet port is used to connect the UTP cable (network cable), which receives data from the PoE Switch to the wall outlet, and the power cable is used to connect it to the outlet. As a result, we have a single network cable that transmits both voltage and data to the terminal or splitter at the other end.

These devices typically have an input range of 100V to AC 240V, an output range of 15V to 48V (via the network cable), an efficiency range of 70-90 percent, and occasionally protection against short circuits, overloads, and voltage spikes. They can tolerate relative humidity levels between 5% and 90% and temperatures between 0°C and 60°C for interiors and -10°C to 70°C for exteriors, though these characteristics differ between models.

2- Terminal Unit or Splitter

The Terminal Unit receives the combined signal (power and data) from the Base Unit, which then separates it once more into power and data. In the process, it also functions as a transformer to deliver the necessary voltage, so you must check the voltage the device to connect uses because it may be 5V/2A, 7.5V/1.5A, or 12V/1A, depending on the device to connect.

To avoid unpleasant surprises or subpar performance, it is also advisable to consider other factors when purchasing a PoE Splitter, such as the maximum and minimum amperage supported or the power in watts.

Advantages of PoE

One of its key features is that since it doesn't require a separate source of energy, we can significantly reduce our expenses. Additionally, since the installation doesn't require a licensed electrician, we can save money on labor costs.

Since PSE devices only supply power when they have first detected that a device is present and enabled for PoE, otherwise no power is supplied along the line, and the PoE infrastructure is typically quite secure. This feature protects both users and equipment from any type of electrical discharge or surge.

Another benefit is that they can be set up to remotely resume, turn off automatically at night, and gather pertinent data from other network-connected devices.

Disadvantages of PoE

The most recent generation of PoE power supplies, despite having some advantages, also has some energy insufficiencies. In particular, as we previously mentioned, they are unable to supply enough power to high-energy devices like network PTZ cameras, even though they can perfectly supply standard cameras with movement.

Another one of its major negatives is that, depending on the technique, if a single power source or switch is typically connected to a number of powered devices, all the devices will cease to function at the same time if any PoE has a problem.

It can also be somewhat expensive because, in order to reduce the risk of the mentioned, we could choose to supply energy to various devices through separate devices for each one. However, this would significantly increase the cost in comparison to other types of solutions on the market, so it is customary to consider even combining PoE with another option.

FAQ
1. What is PoE voltage?

The Ethernet cable receives power over Ethernet at a voltage of between 44 and 57 volts DC, with 48 volts being the most common value. While yet being low enough to be deemed safe, this rather high voltage enables effective energy transfer throughout the cable.

2. What data rate does PoE provide?

Over Cat5, Cat5e, and Cat6 lines, PoE technology can typically deliver 10/100/1000Mbps data rates. PoE technology is anticipated to achieve rates of 2.5Gbps to 5Gbps over 100m today thanks to the broad use of the IEEE 802.3bt PoE standard and PoE++ technology, with future speeds estimated to reach up to 10 Gbps.

3. Does PoE technology have limitations?

Yes, there are several problems with PoE technology. First, the user-accessible places where remote IP-enabled devices could be operated are constrained by the device's shorter range of 328 feet (100 meters). A single PSE, like a PoE switch, can often connect to numerous PDs. All of the PDs will stop functioning if the PSE malfunctions. Consequently, it's crucial to buy high-quality switches from a dependable supplier. You can also think about attaching an uninterruptible power source to the PSE.

4. What are PoE Midspans and PoE Endspans?

The PoE Midspan, also known as a PoE injector, acts as a bridge between a switch that does not support PoE and the device that is powered by a terminal that does. A PoE Endspan, also known as a PoE network switch, connects to a PD directly and provides both data and power through PoE. Endspan PoE sometimes referred to as PoE mode A provides electricity to the data pairs. Midspan PoE, sometimes referred to as PoE mode B, transmits power utilizing pins 4-5 and 7-8. Read the following article to learn more about PoE power supply: How does a PoE switch provide electricity to PoE devices?