Tripp Lite Keyspan USA-49WG Owner's Manual page 19

7.1.e – LED Behavior
The Keyspan USB 4-Port Serial Adapter part number USA-49WG comes equipped with LED lights that report the
status of the Keyspan adapter USB hardware and serial port.
The following table shows all of the possible states of these LED light and what they mean:
Color
Red
Red
Green
(and Red light ON)
Green On-Steady Light
Green On-Blinking Rapidly The Keyspan serial port is sending and/or receiving data.
State Significance
Off The Keyspan adapter is not connected or not receiving power from your
computer.
On The Keyspan adapter is connected and is receiving power from your
computer.
Off The Keyspan adapter software and hardware are working properly.
The Keyspan serial port is available for use.
The Keyspan serial port is 'in use' by an application on your computer and
is ready to send and receive data to and from your serial device.
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