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What is Power Over Ethernet | Datavideo

What is Power Over Ethernet

Jun 01 2022

In recent years, the PoE (Power over Ethernet) applications have become popular. Those who support PoE applications praise the PoE technology very highly; however, those who dislike PoE think PoE is not perfect. The debate between agrees and disagree PoE has made users question whether to adopt PoE. This article introduces you to what PoE is from a practical and objective view.

What is PoE? And how does PoE work? PoE means Power over Ethernet. The PoE technology allows Ethernet cables to transmit data and power simultaneously using a single network cable.   The most typical PoE application is to power the digital video and audio devices.  If the cameras are installed where they are difficult to access, such as on the ceilings and high walls, how do the technical engineer install the facilities' power cords, HDMI cables, and control cables?   If there is an easy-accessible network cable, all the complicated tasks  become much more manageable. 

PoE has several essential accessories which you shouldbe aware of. The first is the Ethernet Switch with PoE function. The network switch can be regarded as the core of the PoE system. Currently, the specifications can be classified into PoE, PoE+, PoE++; Class 0 to Class 8; and Type 1 to Type 4. The user may be confused by the above classification, so we suggest that you can take the following table as a reference.

Type 1 to Type 4 can transmit 12.95W, 25.5W, 51W, and 71W of power to drive the terminal devices within 100 meters. If the terminal devices are IP phones and intelligent door locks, then PoE (Type 1) level network switches are enough. If the terminal devices require high power consumption such as video switchers, cameras, speakers, and LED lighting, you should apply PoE+ (Type 2) to support your applications.

If you want to upgrade your existing equipment to the PoE workflow, you must purchase a PoE Adapter to power your terminal device. The PoE Adapter is the replacement for the AC Adapter.   The PoE integrates the control and video signals to simplify the workflow. In the traditional workflow, the terminal device may use more than three cables- power, video, and control cable, to connect the workflow. However, the PoE workflow uses only one network cable, which significantly reduces the installation cost. Even though the installation of audio-visual equipment is a general project, and anyone can do it, the power system installation requires a qualified electrician technician, which makes the time and labor costs considerable. Considering the installation cost, upgrading existing equipment to PoE workflow is a rewardable solution.

Finally, let's talk about the core facility of the PoE application - the video camera. Many PoE featured applications are on the market, such as IP phones, LED lightings, POS, electronic locks, IP conference systems, Wi-Fi access points, and surveillance facilities.Among the above PoE featured applications, a video camera is an application that fully utilizes the "multiple signal transmission" of the PoE feature. The video camera is not only powered by PoE; the transmission of the camera's control signals, tally lights, and video and audio signals can be compressed into a highly low-latency composite signal over a single network cable. The entry-level PoE cameras can only transmit images by Motion JPEG encoding, while advanced PoE cameras can transmit H.264 and H.265 video. Moreover, the professional PoE cameras support remote control, and various presets for the parameters. It is an easy-to-use solution for remote camera control and video switching.

The PoE applications provide live video producers with an easy-cabling and cost-saving solution. The PoE technology can transmit the power via a single network cable; the power supply socket is no longer considered when installing the terminal devices. Thus, the terminal devices can be flexibly installed in any desired position. On the other hand, the PoE workflow requires fewer power cords than the old-fashioned production workflow. It saves the time, labor, and maintenance costs of the installation by using a network cable.  



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