363-206-305 Trouble Clearing:
TAD-100
Issue 3, June 2000 Page 3 of 6
DDM-2000 F
IBER
R
EACH
N
ARROWBAND
S
HELF
TROUBLE ANALYSIS PROCEDURES
A general knowledge of how the
SLC
-2000 system and DDM-2000 FiberReach NBS
system function and what alarm LED indications mean will aid in performing TAPs
(trouble analysis procedures). TAPs in this volume generally assume the following:
• The system is equipped with the plug-ins required to make an operating system.
• There may be a single cause for multiple trouble indications.
• Only a single trouble cause is assumed to exist.
• The trouble cause is not caused by a carrier system failure.
In case of an alarmed system failure, the craftsperson is first directed to the
SLC
-2000 by an examination of FE (far end), digroup (A, B, C, or D) indicator, and MJ
and MN indication at the CO equipment. Then the
SLC
-2000 Server alarm indicators
provide further trouble isolation information.
When maintenance for the system is the responsibility of a remote maintenance
center, the center will respond to the initial system alarm and dispatch personnel to
the appropriate location (CO or RT) to clear trouble. MLT test results may direct the
craftsperson to the NBS site.
A craftsperson can connect a craft interface terminal (CIT) at a CO DDM/
SLC
-2000
node and remotely log in to the
SLC
-2000 RT and retrieve a fault and alarm list, if the
system is fiber fed.. The fault list can identify several fault conditions at the NBS.
DDM-2000 NBS system trouble clearing normally begins at the
SLC
-2000 using
TAP-101.
Trouble clearing is based on replacement of plug-ins. Any options on replacement
plug-ins must be set per the appropriate facility record. Whenever replacement of a
plug-in does not cure the trouble, the original plug-in should be returned to operation.
The time interval between when a trouble is cleared and when the alarm LEDs go off
is usually less than 35 seconds.
There are several indications that the craftsperson may use to determine whether an
error has been made during system maintenance:
• A new circuit pack (CP) is installed in the RT at turn-up or during maintenance.
The CP's FAIL indicator (LED) should be observed to ensure that it lights
momentarily, then goes off. The absence of this indication should cause the
craftsperson to check for proper CP type, option settings, and location.
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