Managing Alarms
800-357-104-01, Revision 01
74
September 29, 2000
HMS-357 List 4 and List 5
The line unit H1ES, H2ES, and DS1 Errored Seconds Threshold alarms are not supported by the
Shelf Status menu. If any of these conditions exist on a line unit, the line unit status indicates
NORMAL. For this reason, use of the line unit Errored Seconds Threshold alarm option is not
recommended. Refer to the line unit documentation for instructions on setting the Errored Seconds
Threshold option.
Table 10.
Line Unit Alarm Messages
Alarm Message
Definition
Description
LOSW
Loss Of Sync Word
Loss of signal on an HDSL span.
RLOS
Remote Loss Of Signal
Loss of DS1 signal at the remote unit.
LLOS
Local Loss Of Signal
Loss of DSX-1 signal at the line unit.
MAL1, MAL2
Margin Alarm 1, Margin Alarm 2
Loop margin has dropped below the user-set,
minimum threshold level.
NORMAL
No alarm condition exists.
UNKNOWN
Line unit failed to respond to status requests.
Enable the ALM (alarm) option of an unmanaged line unit to allow the unit to trigger an alarm on
pin H of the shelf connector (the LOS Alarm Bus). A managed HLU initiates an HMU alarm message
over the digital management bus between the HLU and HMU. An unmanaged HLU or a T1 repeater
triggers the HMU alarm by driving the LOS Alarm Bus to ground. Refer to the line unit’s
documentation for instructions on enabling the ALM option.