if I recall correctly, it will blink green during setup when talking via the ethernet cable (I did not set my unit up using the wireless connection, so I don't know in that mode)
When it has been configured, when powered up, it will blink green when it registers with the router, then go to solid green when registration has been successfully completed.
In the camera web interface, under Maintenance-Admin, you can turn the LED off using the check box.
If you turn it off, *I believe* it will flash when registering with the router, after that it will go out.