12
Access Unit LEDs
Label
Indication
Color
What It Means
OK
Power and
Operational
Status
Green
ON –
Access unit has power and is
operational.
OFF –
Access unit is in a power-up
self-test, or there is a failure.
Blinking ON and OFF ( Rate: 1 Hz ) –
Software is being downloaded.
ALM
Operational
Alarm ( Fail )
Red
ON –
Access unit has just been reset, or
an error or fault has been detected.
OFF –
No failures have been detected.
TST
Test Mode
Yellow
ON –
Loopback or test pattern in
progress, initiated locally, remotely,
or from the network.
OFF –
No tests are active.
BKP
1
Backup
Yellow
ON –
Access unit is in Backup mode; that
is, the backup link has been
established, and backup is in
progress through the specified
Alternate Destination Link.
OFF –
Access unit is not in Backup mode.
Blinking ON and OFF ( Rate: 1 Hz ) –
Alternate Destination Link is being
established, but no data has been
passed.
1
The BKP LED indicates backup for an ISDN BRI DBM or external backup device.
