HP Ethernet 1Gb 4-port 331T Adapter - Manual (Page 7)

Introduction 7
Item LED Status Description
Flashing (Green) Indicates network activity on the link. The adapter is
sending or receiving network data at up to 1 Gb/s.
2 Link Off No link to the adapter is established. The adapter is not
receiving power or the cable connection is faulty.
On (Yellow) Link to the adapter is established at 10 Mb/s or 100
Mb/s. The adapter is receiving power and the cable
connection is good.
On (Green) Link to the adapter is established at 1 Gb/s. The
adapter is receiving power and the cable connection is
good.