Troubleshooting
150-231-185-05, Revision 05
40
September 13, 1999
HLU-231 List 8E
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 37
S
YSTEM
A
LARMS
lists possible HLU-231 List 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 12.
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-231 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.
Disable the RDA (Remote DS1 Alarm)
option. This prevents an LOS condition at
the DS1 input to a HRU from closing the
alarm contacts (pins 20 and 21 on the
card-edge connector). The front-panel
Status LED still 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 R(L)AIS
(b)
(b) This message is reported in the Span Status screens, but not on the front-panel display. HLU must be connected to HRU-402
or HRU-411 and LPBK option must be set to ENFT.
Remote (or Local)
Alarm Indicating
Signal
Indicates an AIS pattern of all ones is being
transmitted (XMT) from the remote (or
local) T1 output port.
Set LBPK option to ENA or DIS.
ALRM MAL1
or
ALRM MAL2
Margin Alarm
Loop 1
or
Margin Alarm
Loop 2
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 you set 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.
