150-388-125-01, Revision 01
System Alarms
HLU-388 List 2E
September 15, 1998
35
S
YSTEM
A
LARMS
lists possible HLU-388 alarm states. The accompanying front panel message is listed in the
Alarm column. 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
Description
To inhibit:
ALRM LOSW
Loss of Sync Word* 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 DSX-1 input signal.
Disable the RDA (Remote DS1 Alarm)
option. This prevents an LOS condition at
the DS1 input to a HRU from activating Pin
H. 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 TLOS
Transmit Loss of
Signal
The DS1 input is not present at the HRU.
Places the HRU in loopback towards the
network.
Set the TLOS switch at the HRU to disable.
ALRM H1ES
HDSL Loop 1
Errored Seconds
HDSL Loop 1 has exceeded the
user-selected 24-hour Errored Seconds
threshold. If both H1ES and H2ES occur
simultaneously, only H1ES displays on the
front panel.
Set ESAL system option to NONE. See
for more
information.
ALRM H2ES
HDSL Loop 2
Errored Seconds
HDSL Loop 2 has exceeded the
user-selected 24-hour Errored Seconds
threshold. If both H1ES and H2ES occur
simultaneously, only H1ES displays on the
front panel.
Set ESAL system option to NONE. See
for more
information.
ALRM DS1
Bipolar Violations
The total number of bipolar violations
(BVP) at either the HLU-388 or the HRU
DS1 inputs has exceeded the user-selected
24-hour threshold.
Set ESAL system option to NONE. See
for more
information.
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).
*
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.
