PLC device: what is it, what is it for and how does it work

It is possible that, if you are looking for a way to improve the coverage of your Internet connection, you have come across the word PLC. In this guide we are going to explain what exactly a PLC is, how it works and what main uses it has. In addition, we tell you everything you should take into account before buying one for your home or office.

What is a PLC?

PLC is the acronym behind which the expression in English hides Power Line Communications . In Spanish we would say something like “power line communications”. It is true that, in general, this word is used to identify specific devices. But, in reality, it is a technology that uses the electrical network to transmit data and communicate different computer systems. In essence, PLC is the use of a power line to transport digital data.

It is important not to confuse Power Line Communications with Programmable Logic Controller . If you have noticed, both phrases correspond to the same acronyms. A programmable logic controller, or Programmable Logic Controller, is an automaton device that is responsible for controlling sequential processes in industrial machinery. In this article we will focus on the first concept and the devices associated with data transmission technology over the electrical network.

What is a PLC device for?

Para qué sirve un dispositivo PLC

What is a PLC device for

The purpose of a device that uses PLC technology is always the same: take advantage of the existing wired infrastructure to send information. This eliminates the need to install a specific network, for example Ethernet, to transmit data between systems.

Currently, the most frequent use of PLC devices is in the domestic sphere . It is used to extend network coverage to any point in the house where there is a plug. These devices take advantage of the framework of the electrical installation of the house. Thus, they are capable of transmitting the necessary data to provide connection to the local area network and to the Internet.

The use of PLC devices is especially interesting in large homes. The wireless connection provided by the router is limited. If there are a large number of obstacles, such as walls or walls, the most common is that the coverage in certain places is deficient . But thanks to PLC devices, you will have high-speed connectivity in any corner of your home.

Although this type of technology is used mainly in homes, over the years it has had other uses. For example, companies in the electricity sector used PLC technology to become Internet providers . Thanks to the use of the existing electrical infrastructure, they would bring the connection to each home. It is true that it seemed like an interesting idea, but some technical limitations prevented this type of service from becoming a reality. The end result was that the use of PLCs by these companies was relegated to a more technical realm. For example, they allow to know the electricity consumption by a subscriber in real time.

What is better PLC or wifi repeater?

Extending the coverage of your Internet connection is easy with a PLC. Similarly, it is also possible to do it with a Wifi repeater . Which option is the most recommended? In the following sections we analyze this question.

How does a Wifi repeater work

A good way to see the differences between a PLC and a Wifi repeater is to discover the operation of the latter device. Although we will dedicate a section to talk about how PLC devices work, we have already explained that they use the electrical network to transport data packets. The Wifi repeater , for its part, proposes a very different system. It is true that the main objective is the same, that is, to expand the coverage of the Internet connection at home. However, it does so by picking up the wireless signal from the router and replicating it.

To understand it better, think of a house with three floors. The router, which is located on the ground floor, offers good coverage on the first and second levels. However, the signal does not reach the third floor. How does a Wifi repeater solve this problem? If installed on the second floor, it would pick up the wireless connectivity and extend it within its maximum range, extending the signal to the last level of the house. As you can see, they are very effective devices when s and they are located in an intermediate zone between the signal source and the room where coverage is not available.

Advantages and disadvantages of a Wifi repeater

Ventajas y desventajas de un repetidor Wifi
Advantages and disadvantages of a Wifi repeater

A Wifi repeater has some advantages and disadvantages that you should know. Regarding the positive points, this system only requires the installation of a device . A single repeater is enough to extend the coverage of the Wifi network. In addition, they are devices that are very easily configured and do not require technical knowledge to start them up.

If we focus on the disadvantages of Wifi repeaters , we find that they only offer wireless connection. By itself, this has some drawbacks, such as dependence on the router’s signal, loss of speed and a limited coverage radius. In fact, depending on the distances you want to cover, you may need to install more than one repeater.

Advantages and disadvantages of a PLC

If we talk about PLC devices, we also observe some strengths and weaknesses. As for the former, the PLCs are capable of extending the network to any corner , as long as a plug is available. In addition, most emit a Wi-Fi signal, as well as having an Ethernet connector. This obviously makes them more versatile than a repeater. Also, in general terms, they offer higher performance and a more stable connection.

But all that glitters is not gold. The proper functioning of the PLCs will depend on the state of the electrical network in your house . The connection speed may be conditioned by the age of the installation. Another point against is that you will always need two devices. One will be in charge of introducing the data signal into the network and the other of receiving it. Reliance on a plug is another setback. This is usually a problem if you are trying to bring the Internet to specific corners, such as the garden, where it is difficult to find an outlet. And if you were thinking of using your PLC on a power strip, better forget it. Its performance deteriorates notably in that case.

So, PLC or Wifi repeater?

It depends on the characteristics of your home, the distance you want to cover and the type of connection you need. The PLC is recommended if you are looking for a more stable connectivity and want to cover a larger surface . In addition, as they broadcast their own Wi-Fi network, you will have a wireless connection in the adjoining rooms. The PLC is the right option if there are many walls and walls between your router and the place where you want to extend the network. As the signal travels through the electrical installation, that will not be a problem. Of course, before launching to buy a device with these characteristics, make sure that you have a socket where you want the coverage to reach.

Wifi repeaters are a good option in surfaces of moderate dimensions . In that case, acquiring a single device will be more than enough. In addition, their price is usually below that of PLCs and they do not suffer interference due to devices connected to the electrical network. Although if you are looking for an extension of the wide coverage, you will have to buy more than one repeater. Also, they do not offer a wired connection. Therefore, if you need stability and speed, the Wifi repeater is not your device.

How does a PLC work?

To know exactly what the operation of the PLCs is, it is necessary that we clarify some technical concepts . First of all, you should know that the voltage and frequency at which electricity travels through the installation of your home is about 220 V and 50 Hz, respectively. In contrast, PLCs send data at a higher frequency and at a lower voltage. In this way, the device is able to separate the electrical current from the data transmission. Both signals travel through the same cable without interference between them.

At one end of the connection a transmitting PLC must be installed. Once it is connected to the power and to the router, it sends the data provided by the latter throughout the installation. The receiving PLC is connected to another socket, receiving and interpreting the information provided by the transmitter. To send the router signal it is only necessary to have a PLC. However, it is possible to install more than one receiving device to increase the coverage of the network throughout the house. All PLCs will need to be in sync with each other to function properly. This process may vary depending on the manufacturer.

What should be considered when buying a PLC?

Qué hay que tener en cuenta al comprar un PLC

What must be considered when buying a PLC

We finish this guide by talking about all the points that you should take into account before buying a PLC device.

Connections

The connections are one of the most important points that you should know when getting your PLC device. Mainly, they include two types: Ethernet and Wifi.

    • Ethernet . The wired connection via Ethernet is the main gateway to the data received from your PLC receiver. Basic models usually include only one port, while more advanced models include two or more. If you want to use the Ethernet connection with more than two computers, consider the possibility of purchasing a PLC with multiple ports. Also make sure that it has a Gigabit interface to enjoy the maximum speed when connecting your computer to the network.
    • Wifi. Having Wifi in your PLC will be very useful in some circumstances. If you have considered buying this type of device, it is because your router is not capable of covering all the rooms in your home. Having a Wi-Fi connection will allow you to use mobile phones, tablets and other equipment that do not have an Ethernet port. A PLC with Wifi helps you meet two needs: provide a connection to your computer and repeat the wireless signal from your router. Of course, make sure that the chosen device has the latest Wifi standard on the market.

Standard used

PLCs use a standard called Homeplug . Thanks to it, they are devices capable of transporting data through the electrical network. This regulatory framework used by PLCs has been improving over the years. Next, we leave you a list with all the versions of Homeplug that exist. Remember that the most recent versions stand out for offering better performance.

      • AV. First known standard for transporting data packets using electrical installations. It appeared in 2001, it had a maximum bandwidth of 14 Mbps and a real speed of 4.2 Mbps.
      • AV200 . Evolution of the first version with a potential bandwidth of 85 Mbps. The 10/100 Mbps Ethernet interface was used.
      • AV500 : Another evolution that started from the first specification. It was able to deliver theoretical speeds of 500 Mbps and 300 meter cabling coverage.
      • AV600 : Increase from 500 Mbps to 600 Mbps with respect to the previous standard.
      • AV2 . It is the second version of Homeplug. At the time, it supported speeds from up to 600 Mbps to 1000 Mbps.
      • AV2-1200 . Evolution of AV2 that raises the speed to 1200 Mbps. A chipset compatible with MIMO was used that was able to modulate the Ethernet traffic in two channels.
      • AV2-2000 . Latest standard with a theoretical throughput of 2000 Mbps.

Connection speed

This is an aspect closely related to the previous point. The maximum speed of the PLC model you choose must be equal to or greater than the speed of your Internet connection. Only then can you make the most of its performance. However, keep in mind that the speed supported by each standard is theoretical and refers to the maximum achievable under optimal conditions. For example, with an AV2-1200 PLC that supports up to 1200 Mbps, you are likely to be browsing at a speed between 500 and 700 Mbps.

Plug included

Using a PLC means losing at least two sockets at home. Fortunately, there is a simple solution to this problem. We refer to choosing a model that includes a plug . You can connect another electrical appliance or even a power strip to it. This way you preserve all the plugs in your house, while transporting the Internet connection through the electrical network.

Interference in the network

PLC devices suffer interference when connected together with high-power devices, such as a dishwasher. This affects the stability of the connection and the speed. To solve this problem, it is important to connect the PLC to a socket that is far from the main electrical appliances in your home. If for some reason this is not possible, consider the possibility of buying a Wifi repeater that does not depend on the electrical network.

Characteristics of your electrical network and your home

Some characteristics of the electrical installation of your home may condition the correct operation of the PLC devices. For example, both the sender and the receiver must be connected to the same network . If your intention is to extend the coverage between two different buildings, it is necessary that they share a facility. In the same way, it is possible that your house has two different networks for each floor. In that case, the PLCs will not work.

On the other hand, take a look at the specifications of the chosen model in search of the maximum supported range. If the distance between the two devices is greater, you should look for different options, such as purchasing a more advanced PLC or installing multiple Wifi repeaters.

Price

We close this section by talking about the price. The most common is that manufacturers market their PLCs in pairs, including the transmitter and the receiver. As is usually the case, devices that include a greater number of functions are more expensive. Thus, the final price will depend on the characteristics you need in your case. A couple PLC with speeds of up to 500 Mbps with Wifi has an approximate price of about 80 euros .