IP video surveillance camera - the features of PoE technology

One of the main advantages of IP-cameras is the support of PoE technology (PoweroverEthernet). The IEEE 802.3af standard provides Cat 5 and above ordinary twisted pair transmission of the voltage of up to 48V, for power devices that use up to 15.4W. In this way, the camera will be able to connect to the power supply and the router via the same cable, when connected to the Ethernet network equipment capable of transmitting the current into the line and separating it from the transmitted digital information.

IP-cameras supporting PoE technology are equipped with a splitter responsible for performing the second task - the distribution of the received power and the data being sent, and, consequently, they do not require connection to a regular household 220V network or other power source other than a UTP cable. Purchasing such a device allows saving considerable amount of money on installation of additional communications and on maintenance of the security system in working condition in principle.

How to connect an IP camera to the electric power supply via the Ethernet network

There are several ways to connect cameras with PoweroverEthernet support:

Mid-span. The optional Ethernet network, also called the mid-span, is plugged into a socket and connected between the camera and the router. The energy will be transmitted only to the device consuming it if it is at a distance of no more than 150 meters, and only data will flow to the router.
End-span. The Ethernet switch already supports PoE technology and it is equipped with the appropriate connectors that transmit both energy and data.

IP cameras that do not support such a standard of power supply can be called a rarity today, but they can be freed from the need to connect to the socket, with the usage of the same mid-span and a converter. Such a solution is called PassivePoE and it is implemented as follows: after the server, a mid-span that transmits the power supply is installed on the line, after which a splitter separates the energy from the data and then transmits it via two different connectors to the camera. The second case is when it may be necessary to integrate these two additional modules into the system, it is used for the observation of PTZ devices. Cameras with a varifocal lens or a rotary mechanism that can be controlled at a distance through the same twisted pair consume several times more power. Thus, 3.5W can be enough for the ordinary IP devices, PTZ devices that support the next generation of the IEEE 802.3at standard or PoE + standard may need up to 60W.