LTPH-UM-1049-02, Issue 2 Testing
H2TU-C-319 List 4E January 9, 2002 53
Alarm Option for the Digital Loop Carrier Feed
To improve HiGain HDSL2 compatibility with the switch-to-protect features used in the Digital Loop Carrier
(DLC) feeder applications, the H2TU-C has an Alarm Pattern (ALMP) option that allows you to select either an
AIS or LOS DS1 output payload for the following a larms:
LOSW on any loop
LOS DS1
Retiring System Alarms
To retire a system alarm, press the LBK pushbutton and execute an Alarm Cutoff (ACO). An ACO turns the alarm
off and replaces the ALRM message with an ACO message. The second part of the ALRM message, which defines
the cause of the alarm, remains. Both parts of the message remain until the alarm condition clears or another higher
priority alarm occurs.
xxx-HBER(b) HDSL2 Block Error
Rate The HDSL2 BER has exceeded the set threshold
limits of 10-6 or 10- 7. (xxx denotes either TUC or
TUR. If TUC and TUR occur at the same time, then
TUC displays.)
Select NONE for the HBER
system option.
xxx-MAL Margin Alarm The margin on the HDSL2 loop has dropped below
the minimum threshold value set for the system.
(xxx denotes either TUC or TUR. If TUC and TUR
occur at the same time, then TUC displays.)
Set the Margin Alarm
Threshold option to 0 (zero).
xxx-LA Loop Attenuation The attenuation on the HDSL2 loop has exceeded the
maximum value set for the HDSL2 loop attenuation
threshold. (xxx denotes either TUC or TUR. If TUC
and TUR occur at the same time, then TUC displays.)
Set the HDSL2 Loop
Attenuation Threshold
option to zero.
(a) The message, ALRM, displays prior to any alarm message.
(b) Only these alarms assert the System Alarm bus on pin H of the card edge connector, if the alarm system is set to ENABLE.
(c) When the HDSL2 loop loses sync word (LOSW), a system alarm condition exists. The H2TU-C enters the acquiring mode,
the front panel status LED flashes red, and the ACQ or SIG message displays instead of the ALRM message.
Table 21. Front-Panel System Alarms Summary (Continued)
Front-Panel
Message (a) Alarm Description To Inhibit: