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Chapter 11: Troubleshooting
Power Over Ethernet
226
This section applies only to the AT-SBx81GP24 Line Card. Each port has
two LEDs. The left LED provides port link and activity status and the right
LED provides PoE status information. The PoE LED is solid green when a
port is delivering power to a powered device (PD). The PoE LED of a port
that is not delivering power will be flashing amber, steady amber, or off. If
a powered device is not receiving power from a port on the line card, try
the following:
If all the L/A LEDs on the line cards in the chassis are off, try
pressing the eco-friendly button on the active master controller
card to turn on the LEDs.
Check to be sure that the chassis has at least one AT-
SBxPWRPOE1 Power Supply and that the unit is operating
properly. The AC and DC LEDs should be solid green and the
Fault LED should be off. For troubleshooting suggestions, refer to
"AT-SBxPWRSYS1, AT-SBxPWRSYS2, and AT-SBxPWRPOE1
Power Supplies" on page 218.
Review the PD's documentation to confirm that it supports Mode A
of the IEEE 802.3at standard. Mode A is one of two modes that
define the connector pins that deliver the power from the port on
the line card to the PD. In Mode A, the power is carried on pins 1,
2, 3, and 6 on the RJ-45 port, the same pins that carry the network
traffic. The second mode, Mode B, defines pins 4, 5, 7, and 8 as
the power carriers. The AT-SBx81GP24 Line Card does not
support Mode B. Most powered devices are designed to accept
power by either mode, but some legacy devices may only support
one mode. This can be verified by reviewing the device's
documentation or data sheet. Legacy devices that only support
Mode B will not work with this line card.
Review the device's documentation or data sheet to confirm that its
power requirements do not exceed 30 W.
Verify that you are using the appropriate category of twisted-pair
cable by referring to Table 18 on page 60.
Try replacing the twisted-pair cable, as explained in "Cabling
Guidelines for the Twisted Pair Ports" on page 154.
Use the SHOW POWER-INLINE command in the management
software to determine whether PoE is enabled on the port. The
default setting for PoE is enabled.
Use the SHOW POWER-INLINE command to determine whether
the PoE power setting for the port has been reduced from the
default setting of 30 W, to a value below the power requirements of
the device.
Use the SHOW POWER-INLINE command to determine whether
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