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13.10 Description of PoE [AX2200S] [AX1240S]
13.10.1 Overview of PoE
PoE (Power over Ethernet) supplies power to network devices by using an RJ45 cable,
which is normally a cable used for data communication. It can supply a maximum of 30.0 W
of power. An AX2200S series switch can supply a maximum of 60.0 W of power.
PoE is used for network devices installed at locations where external power is not readily
available. In PoE, the power supplier is called power sourcing equipment (PSE), and the
power receiver is called a powered device (PD).
The Switch, which is a PSE that complies with the IEEE 802.3af and EEE802.3at standards,
automatically performs three processes: detecting the PD (detection process), classifying
the level of power required by the PD (power level classification process), and supplying
power (power supply process).
(1) Detection process
The detection process detects whether the connected device is a PD. If the connected
device is a PD that complies with the IEEE 802.3af or IEEE802.3at standards, the
processing proceeds to the next power level classification process. Note, however, that the
switch does not supply power to a network device that does not support PoE.
(2) Power level classification process
In the power level classification process, the power level of the PD is determined by the use
of a special voltage defined in the IEEE802.3af and IEEE802.3at standards. The PD
recognizes that it is in the power level classification process due to the special voltage
supplied from the Switch. At this time, the Switch can determine which of the five power
classes the PD belongs to by how the PD consumes the current (also defined in the
IEEE802.3af and IEEE802.3at standards). Note that because power level classification is
prescribed as optional in the IEEE 802.3af standard, not all PDs always support such
power level classifications. A device that does not support this classification is classified as
Class 0.
(3) Power supply process
Based on the PD's demand, the Switch can supply power up to the maximum output power
shown in Table 13-24 Power class and maximum output power of the Switch.
Table 13-24 Power class and maximum output power of the Switch
Power class
Class 0
Class 1
Class 2
Class 3
Class 4
13.10.2 Allocating the power supplied by PoE [AX2200S]
AX2200S series switches can supply 60.0 W of power, in addition to complying with the
IEEE802.3af and IEEE802.3at standards. As shown in the figure below, AX2200S series
switches can supply 60.0 W on ports 0/1 to 0/4 (system 1). They can also supply a
Maximum output power
15.4 W
4.0 W
7.0 W
15.4 W
30.0 W
13 Ethernet
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