Power over Ethernet or PoE describes any of several standardized or ad-hoc systems which pass electrical power along with data on Ethernet cabling. This allows a single cable to provide both data connection and electrical power to devices such as wireless access points or IP cameras. Unlike standards such as Universal Serial Bus which also power devices over the data cables, PoE allows long cable lengths. Power may be carried on the same conductors as the data, or it may be carried on dedicated conductors in the same cable. There are several common techniques for transmitting power over Ethernet cabling. Two of them have been standardized by IEEE 802.3. Since only two of the four pairs are needed for 10BASE-T or 100BASE-TX, power may be transmitted on the unused conductors of a cable. In the IEEE standards, this is referred to as Alternative B. Power may also be transmitted on the data conductors by applying a common-mode voltage to each pair. Because twisted-pair Ethernet uses differential signalling, this does not interfere with data transmission. The common mode voltage is easily extracted using the center tap of the standard Ethernet pulse transformer. This is similar to the phantom power technique commonly used for powering audio microphones. In the IEEE standards, this is referred to as Alternative A. In addition to standardizing existing practice for spare-pair and common-mode data pair power transmission, the IEEE PoE standards provide for signalling between the power source equipment (PSE) and powered device (PD). This signaling allows the presence of a conformant device to be detected by the power source, and allows the device and source to negotiate the amount of power required or available. Up to a theoretical 51 watts is available for a device, depending on the version of the standard in use and the vendor of the hardware.
- Brand : Ubiquiti
- Hardware Interface : Ethernet
- Product Dimensions : 7 x 8.8 x 3.3 cm; 135 Grams
- Data Link Protocol : IEEE 802.3, Ethernet
Product key features:
- The IEEE standard for PoE requires category 5 cable or higher for high power levels, but can operate with category 3 cable if less power is required. Power is supplied in common mode over two or more of the differential pairs of wires found in the Ethernet cables and comes from a power supply within a PoE-enabled networking device such as an Ethernet switch or can be injected into a cable run with a midspan power supply.
- This POE is 24V DC and works only with Ubiquiti wireless devices and nothing else.
- This device cannot be used with any POE camera
- We have supplied many for maintenance work
- Warranty not applicable for this product.