User's Manual
AT-2900 Series Gigabit Ethernet Network Adapters Installation Guide
109
Checking Port LEDs on the Adapter
The adapter has two LEDs: LINK and ACT. The LINK LED indicates an 
active link and the ACT (Activity) LED indicates data transfer status. Once 
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. 
Before the port LEDs can provide troubleshooting information, the adapter 
must be connected to the network (see Chapter 2, “Installing the 
Hardware” on page 21) and the network drivers for your particular 
operating system must be installed. 
1. Verify that the adapter driver software has been installed and that the 
adapter is connected to a network. 
2. Check to see that the LEDs operate as described in Table 5.
Table 5. 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 card and the 
switch.
Off Data traffic is not present. 










