Allied Telesis AT-2972T/2 - Manual (Page 18)

Chapter 1: Introduction to the AT-29xx Series Gigabit Ethernet Network Adapters
18
LEDs
All fiber adapter models have two LEDs: LINK and ACT. The LINK LED
indicates an active link and the ACT (Activity) LED indicates data transfer
status. After the driver is loaded and the cables are connected properly.
The LINK LED is lit and the ACT LED is on if data traffic is present. See
Table 1.
The AT-2972T/2 has one copper port with a single LED. For a description,
see Table 2.
Table 1. Fiber Optic Port LED Status
LED State Description
LINK On Valid fiber link.
Off No fiber link.
ACT Blinking Data traffic is present
between the adapter and
the switch.
Off Data traffic is not present.
Table 2. AT-2972T/2 LED
State Description
On Valid link.
Off No valid link.
Blinking Data traffic is present between the adapter and the switch.