150-388-151-01, Revision 01
Troubleshooting
HLU-388 List 5A
September 15, 1999
43
T
ROUBLESHOOTING
This section provides information about system alarms and loopback testing. In addition to these troubleshooting
aids, the Maintenance Terminal provisioning interface includes troubleshooting screens that provide a basic
graphical analysis of system problems. (See
“View Troubleshooting Screen” on page 39
S
YSTEM
A
LARMS
lists possible HLU-388 List 5A alarm states and the corresponding front-panel messages. More than one
alarm condition can exist at any given time, but only one message can be displayed. For multiple alarms, only the
highest priority alarm displays.
Table 13.
HDSL System Alarms
Front Panel
Message
Alarm State
Description
To Inhibit:
ALRM LOSW
Loss of Sync
Word
(a)
(a) When both HDSL loops lose sync word (LOSW), a system alarm condition exists. However, since the HLU-388 enters a self
test cycling mode, the front panel LED lights yellow instead of red and the
SELF TEST
message displays instead of the
ALRM
message.
One of the HDSL loops has lost
synchronization.
Cannot be inhibited.
ALRM LLOS
Local Loss of Signal Loss of the DSX-1 input signal.
Cannot be inhibited.
ALRM RLOS
Remote Loss of
Signal
Loss of the HRU DS1 input signal.
The front-panel Status LED flashes red and
the ALRM RLOS message displays to alert
you of the LOS state. LOS is sent towards
the network from the HLU. This option
prevents the common occurrences of a
CPE LOS condition from generating
recurring alarms and AIS payloads.
ALRM MAL1
or
ALRM MAL2
Margin Alarm
Loop1
or
Margin Alarm
Loop2
The margin on HDSL Loop 1 or Loop 2 has
dropped below the minimum threshold
value set by the terminal MARGIN ALARM
THRES.
Set the Margin Alarm Threshold option to 0
(zero).
ALRM BER
Bit Error Rate
exceeded
The combined T1 and HDSL BER has
exceeded the threshold limits of 10
-6
or 10
- 7
.
Select NONE for the BER system option.
NONE
No alarm
No current alarm condition.
Cannot be inhibited.