IP CCTV cameras POE. What is PoE in CCTV cameras? IP cameras with poe connection

IP CCTV Cameras POE differ from other models in the way they transmit power. They do not require a separate power cable and can receive electricity through a network cable or twisted pair. This approach allows you to speed up the process of creating a security system. All you need to do to get started is to install the “Power over ethernet” video camera and connect it through the injector to the corresponding connector of the switch or DVR. Today, the devices are very popular and are used for surveillance not only in the private sector, but also in offices, shops and shopping centers. Depending on the functionality, you can find a POE IP surveillance camera in dome, rotating and street types. All of them are designed to solve video recording problems and can have a digital speaker or microphone built into the body. With their help, the user will be able to not only view the image on the monitor in real time, but also listen to the conversations of people located in the protected area. For shooting at night, video cameras are equipped with IR illumination built into the body with a distance of up to 200 meters and automatic activation of the spotlight in the dark.

POE IP CCTV Camera Systems

POE IP surveillance cameras will reduce the time required to create a video system, as well as raise its reliability to a new level. Their main difference from other equipment is the ability to transmit electricity over a twisted pair Ethernet cable using a switch or injector. Thanks to this, there is no need to lay the power cable, which has a positive effect on ease of use and increases the efficiency of the security system. You can purchase network devices for indoor and outdoor installation with a sealed IP66 housing. Here you will find dome, street and rotary models.

Selecting a POE IP CCTV Camera

The process of selecting a powered network video camera is identical to selecting conventional equipment. However, it differs from it in that, in addition to the resolution of the matrix, the distance of the IR illumination and the shape of the case, it requires additional consideration of such parameters as the standard of this technology, as well as the source voltage.

• The first step is to figure out what standard the devices support. There can be two options here, IEEE 802.3af-2003 and IEEE 802.3at-2009. They differ from each other in current, power and voltage. Therefore, before purchasing a POE IP CCTV camera, it is recommended that you carefully study the power supply issue.
• Next, it is worth studying the issue of matrix resolution, IR illumination distance and the possibility of installing the device outdoors. For use in a home security system, surveillance cameras with a matrix of 2 to 3 megapixels and infrared illumination up to 25 meters are most often chosen.

Price of IP CCTV cameras POE

For POE IP surveillance cameras, the price depends on which standard is supported by the equipment. Today, all presented devices are designed to work with either IEEE 802.3af-2003 or IEEE 802.3at-2009. The first has a lower cost and is designed to power stationary dome and street video cameras, but is not sufficient for PTZ devices. Therefore, if you have a need to control the lens via the Internet, then you will be better suited to devices whose price is higher, but which are compatible with IEEE 802.3at-2009.

The PoE standard eliminates the need for conventional power cables and outlets, allowing power to be transmitted along with video and control signals over twisted pair cables.

Many people call IP cameras the future of video surveillance systems, and, admittedly, for good reason. They have a number of advantages compared to common analog devices, first of all, better image detail. Modern IP cameras are capable of producing images of not only quality HD 720p, but also Full HD 1080p. The highest detail will help you see even such small details like a human face or a license plate, and even at quite a considerable distance.

Unlike analog CCTV cameras that transmit signals via coaxial cable, IP cameras transmit data via twisted pair cable (with the exception of Wi-Fi cameras equipped with a built-in Wi-Fi module). Installing such cameras instead of analog ones entails reworking a fair part of the entire video surveillance system, which for many is a disadvantage of IP devices. And indeed, the more you have to redo, the more money you will have to spend - this, alas, is an axiom.

But there is such a thing as PoE technology, or Power over Ethernet. This useful technology was presented to the general public a long time ago, in 2003, but only in recent years has it found wide application, including in video surveillance networks. If we describe its essence briefly, we can say the following: the PoE standard allows you to do without conventional wires and power outlets, allowing you to transmit electricity along with signals over twisted pair. Need I say that this not only saves money by making it unnecessary to lay electrical wiring to the locations of IP video cameras and install sockets there, but also facilitates the process of installing new devices?

In fact, PoE technology is an efficient alternative method of power supply to various network devices. Its effectiveness lies in the fact that thanks to it, it has become possible to quite simply install surveillance cameras and other network devices where laying electrical wiring is difficult or completely impossible. This problem can arise both when designing a new network or when upgrading an existing one, and this is where IP cameras with PoE support come to the rescue. Thus, it can be very effective to install video cameras with Wi-Fi and PoE where the router signal is strongest, but there are no electrical wires and sockets. Without PoE, installing the camera in such a convenient location would have been impossible, but with PoE it would have been easy.

The question is often asked: doesn’t the fact that power is supplied via twisted pair affect the quality of the signal? You can authoritatively say - no, there is no influence. To transmit energy via twisted pair, the physical properties of Ethernet technology are used, especially since modern cables for Ethernet connections have four pairs, of which only two are used.

In the case of IP video cameras with PoE support, power is supplied via the RJ-45 port, and the power source is a PoE switch or PoE injector, used in some networks as intermediate power supply equipment. According to the standard involved, a voltage of 45V is supplied through the modern Ethernet cable described above, which provides an output power of 15 Watts. Due to the fact that the voltage is high enough, there is no need to use cables with a large conductor cross-section, which reduces the cost of the technology.

Thus, IP cameras with PoE have a number of advantages compared to conventional digital devices that do not support this technology:

• The range of IP video cameras with PoE is not inferior to the range of similar cameras without this technology. Although this circumstance, strictly speaking, is not an advantage.
• Thanks to IP cameras with PoE, the procedure for upgrading existing video surveillance networks is simplified, largely due to the fact that it becomes possible to install cameras where there is no electrical wiring and sockets.
• Installing cameras with PoE is easier than installing conventional cameras, again due to the lack of need to run electrical wiring to the camera.
• The prices of PoE IP cameras are not that much different from the prices of regular digital cameras.

True, twisted pair cables have a distance limit, beyond which the quality of the IP signal can deteriorate unpredictably. The critical distance is one hundred meters, according to the current Ethernet standard. This is precisely the maximum length of one cable segment for signal transmission, and, unfortunately, it will not be possible to bypass this limitation by installing a PoE injector. But there is another way out - for example, install a media converter that converts a twisted pair line into optical fiber. However, installing a media converter will entail additional work and costs.

If you decide to use PoE video cameras in your network, you should also take care of choosing the right PoE switch. Different switch models have different power budgets. Simply put, one switch can ensure uninterrupted operation of a certain number of cameras, but no more. Of course, the more cameras it can support, the more expensive it is. A certain kind of dilemma arises here - on the one hand, there is no point in overpaying for a more powerful switch, but on the other hand, you will have to buy a new one if you decide to increase the number of PoE cameras used. Unfortunately, PoE switches cannot be upgraded.

It doesn’t always make sense to build an entire video surveillance system using IP video cameras with PoE. If some of the cameras are supposed to be placed where there are no problems with the power supply, or, moreover, wiring and a socket are already connected to the camera, then there is no point in overpaying for PoE - a regular IP camera will cope with the task no worse. But if in some places on the site there are difficulties with the power supply, then PoE technology will come in handy, since there are enough camera models on the market to suit every taste and budget.

© website Use and reprinting of material is permitted only with written permission from the company.

When modifying existing ones, the owner often faces difficulties.

In particular, when replacing cameras in order to obtain greater surveillance capabilities and remote access via computer networks, inconsistencies or insufficient functionality of cable routes may be discovered.

It is easy to encounter supply voltage mismatch. An IP PoE camera can solve the problems that arise.

Such a device only needs one twisted-pair cable line to receive the required power and transmit a signal.

How PoE technology works in CCTV cameras

Understanding what PoE is in CCTV cameras is quite simple.

This is a technology for transmitting electrical power and exchanging signals between master and slave equipment.

At the same time, depending on the implementation mechanics, modern devices may contain:

1. mandatory mechanics for coordinating the parameters of the consumer and the power source;
2. transmission of signal and power over the same conductors;
3. separation of cable pairs to perform separate groups of functions (power supply and transmission).

When building a specific video surveillance network, you may not encounter the limitations of PoE.

To overcome them, intermediate amplification devices, switches and injectors are used.

The type and number of these devices, as well as the need for their use, are dictated by the specific implementation of the PoE protocol.

PoE classification

PoE video surveillance uses fairly simple mechanics of interaction between the master and slave devices.

Mandatory intermediate equipment is used to transmit electrical power and simultaneous signal transfer.

This device is called an injector and without it it is impossible to organize the operation of a video surveillance system.

In addition to the general interaction scheme, there are features of the network organization. The first thing to evaluate is the cameras' power requirements.

It can range from 5 Watts for household devices equipped with IR illumination, to 15 Watts for models capable of changing position and focusing using electric drives. Individual PoE video cameras can consume up to 30 watts of electrical power.

Modern surveillance devices can interface with almost any version of the power-data protocol.

However, to optimally plan your investment, it is worth evaluating PoE surveillance cameras, injectors used, and other equipment.

The PoE protocol is divided into two large groups: the so-called smart and passive. Most of the divisions belong to the first segment (IEEE 802.3af, 802.3at, 802.3bt versions).

Here the classification looks like this:

• up to 15.4 Watt for the 802.3af protocol version;
• up to 30 Watt for IEEE 802.3at;
• up to 100 watts for 802.3bt.

The second classification criterion applies to single and group injectors:

1. class 1 is capable of transmitting up to 4.5 W of power per port, the permissible range for 1 camera is from 0.44 to 3.84 W;
2. class 2 has a maximum of 7 watts, from 3.84 to 6.49 watts per consumer;
3. class 3 - 15.4 Watts per port, 6.49-12.95 per consumer;
4. class 0 - maximum 15.4 watts, 0.44-12.95 watts per camera.

This classification criterion is taken into account when developing a data transmission network.

The correct choice of injectors and chamber connection diagrams can significantly reduce the overall cost of purchasing equipment.

Smart PoE is characterized by the simultaneous use of cable pairs (4 pieces) for power supply and signal transmission. Passive exchange mode is simpler.

Its implementation uses the principle of separating the functionality of cable pairs. Some of them are used to transmit signals, and some are used to transmit power.

Advantages and Limitations of PoE Technology

Understanding what PoE is in video surveillance and the basic principles of protocol implementation, it is easy to see the pros and cons of the technology. Their set depends on what kind of exchange mechanics are used.

For smart PoE, the advantages include:

• mandatory power coordination that occurs when the camera is turned on;
• The range of equipment for managing and regulating the operation of the network is very wide. Switches, group injectors are available. Easy to set up scheduling and remote control;
• with a line length of up to 100 meters, there are no difficulties in building the structure.

The disadvantages of active smart technology are, first of all, the significant cost of the equipment. But they are easily compensated by the full range of supported protocols and the high fault tolerance of the cameras thanks to power matching.

When using the passive version of PoE, the consumer receives the following benefits:

1. low price for equipment;
2. the ability to use combined cables as signal lines (not);
3. transfer of significant power.

But the disadvantages are more significant:

• Even with lines up to 100 meters long, power failures and signal interference are possible. They are more significant, the greater the electrical power transmitted to operate the camera;
• it is necessary to select devices that can work with the passive version of the protocol;
• There is no mandatory power coordination when the camera is turned on, which can lead to various emergency situations.

These features of PoE versions have led to the widespread use of active smart systems.

However, it is worth noting that passive mechanics are still used in a large number of ready-made solutions offered to the consumer.

Conclusion

Using the advantages of the PoE protocol, it is easy to minimize the number of cable runs, eliminate the need to mount power supplies near the consumer, and solve many problems when modifying existing video surveillance systems.

The active smart version guarantees cost optimization for building an engineering solution for the monitoring network. And at the same time, reverse support for passive mechanics will ensure easy use of cameras and equipment of different classes within the same video surveillance structure.

Video: PoE for IP camera at 100 meters. And at 300 meters?

Content

POE is a technology for transmitting signal and power over one twisted pair cable to Ethernet network devices. The use of poe in IP cameras has made life much easier for installers of IP systems, since there is no need for additional cabling for the voltage supply.

POE (Power over Ethernet - literally Power over the Ethernet standard) allows you to provide a current of up to 400 mA with a voltage rating of 48 V, through 4 cores (2 pairs) of twisted pair, the remaining 2 pairs of cable are used for signal transmission. Maximum POE power 15.4W.

Power supply device (POE switch or switch) - supplies the camera with a signal and power at a distance of up to 150 meters, while constantly testing its power consumption in order to further manage the necessary power for the connected device and prevent voltage supply above or below its operating norm .

Connecting an IP camera with and without poe using technology (Power over Ethernet)

To connect a POE IP camera using the POE standard, you need a POE switch or a DVR with built-in Poe ports. A 4-pair twisted pair cable connects the poe network port of a switch or DVR to the camera port, thereby providing power supply. Connecting a poe switch to any router or DVR without poe occurs through the UPlink port.

Below is a diagram of connecting a camera with and without POE using Power over Ethernet technology. In the second case, a poe splitter is additionally used at the end of which there are two connectors: for connecting to the camera’s Etherent port and DC “Male” for connecting to the “Female” power supply.

Passive POE

Now it has become fashionable to talk about passive poe, calling it technology; in fact, it is a banal homemade product that is just a little more convenient. One passive adapter with a male connector is connected on the camera side, and the second with a female connector is connected on the side of the 12 volt power supply.

There can be no talk of 150 meters of transmission, at best, through a cable with a good cross-section of 60 meters, and then you definitely need to check what voltage is coming out at the camera’s power plug, if it’s below 11 volts, then the device will break down in a short time. Such a circuit can be organized directly without an adapter, simply by installing power strips on two free cable pairs.

On video: Connecting IP cameras via POE