ZyXEL Communications XGS2220 Series User Manual page 585

Table 338 Port > PoE Setup > PoE Setup (continued)
LABEL DESCRIPTION
Priority When the total power requested by the PDs exceeds the total PoE power budget on the Switch,
you can set the PD priority to allow the Switch to provide power to ports with higher priority.
Select Critical to give the highest PD priority on the port.
Select High to set the Switch to assign the remaining power to the port after all critical priority
ports are served.
Select Low to set the Switch to assign the remaining power to the port after all critical and high
priority ports are served.
Power-Up Set how the Switch provides power to a connected PD at power-up.
802.3af – the Switch follows the IEEE 802.3af Power over Ethernet standard to supply power to the
connected PDs during power-up.
Legacy – the Switch can provide power to the connected PDs that require high inrush currents at
power-up. Inrush current is the maximum, instantaneous input current drawn by the PD when first
turned on.
Pre-802.3at – the Switch initially offers power on the port according to the IEEE 802.3af standard,
and then switches to support the IEEE 802.3at standard within 75 milliseconds after a PD is
connected to the port. Select this option if the Switch is performing 2-event Layer-1 classification
(PoE+ hardware classification) or the connected PD is NOT performing Layer 2 power
classification using Link Layer Discovery Protocol (LLDP).
802.3at – the Switch supports the IEEE 802.3at High Power over Ethernet standard and can supply
power of up to 30 W per Ethernet port. IEEE 802.3at is also known as PoE+ or PoE Plus. An IEEE
802.3at compatible device is referred to as Type 2. Power Class 4 (High Power) can only be used
by Type 2 devices. If the connected PD requires a Class 4 current when it is turned on, it will be
powered up in this mode.
Force-802.3at – the Switch offers power of up to 33 W on the port without performing PoE
hardware classification. Select this option if the connected PD does not comply with any PoE
standard and requests power higher than a standard power limit.
Pre-802.3bt – the Switch offers power on the port according to the IEEE 802.3bt standard. Select
this option if the connected PD was developed before the IEEE 802.3bt standard is implemented
but requires power between 33 W and 60 W. IEEE 802.3bt is also known as PoE++ or PoE Plus Plus.
802.3bt – the Switch supports the IEEE 802.3bt standard and can supply power of up to 60 W per
Ethernet port to the connected PDs at power-up.
Max Power Specify the maximum amount of power the PD could use from the Switch on this port. If you leave
(mW) this field blank, the Switch refers to the standard or default maximum power for each class.
LLDP Power Via Select this to have the Switch negotiate PoE power with the PD connected to the port by
MDI transmitting LLDP Power Via MDI TLV frames. This helps the Switch allocate less power to the PD on
this port. The connected PD must be able to request PoE power through LLDP.
The Power Via MDI TLV allows PoE devices to advertise and discover the MDI power support
capabilities of the sending port on the remote device.
• Port Class
• MDI Supported
• MDI Enabled
• Pair Controllable
• PSE Power Pairs
• Power Class
Apply Click Apply to save your changes to the Switch's run-time memory. The Switch loses these
changes if it is turned off or loses power, so use the Save link on the top navigation panel to save
your changes to the non-volatile memory when you are done configuring.
Cancel Click Cancel to begin configuring this screen afresh.
Chapter 79 Networked AV Mode
XGS2220 Series User's Guide
585