Nortel 1000E Maintenance Manual page 39

Table 4
NTBK50 faceplate LEDs (Part 2 of 2)
LED
CC Flashing (Green)
DCH
NTRB21 Faceplate LEDs
State Definition
The NTAK20 is equipped and is attempting to lock
(tracking mode) to a reference. If the LED flashes
continuously over an extended period of time, check the
CC STAT in LD 60. If the CC is tracking, this can be an
acceptable state. Check for slips and related clock
controller error conditions. If none exist, then this state is
acceptable, and the flashing is identifying jitter on the
reference.
Off The clock controller is not equipped.
On (Red) The DCH is disabled.
On (Green) The DCH is enabled, but not necessarily established.
Off The DCH is not equipped.
The NTRB21 1.5 Mbit DTI/PRI/DCH circuit card has a total of seven
faceplate LEDs. Five of the LEDs are directly associated with the operation
of the NTRB21 circuit card. The remaining two LEDs are associated with the
optional daughterboards. The first of these LEDs is used to indicate the status
of the NTAK20 Clock Controller daughterboard. The second LED indicates
the status of the D-channel interface.
Hardware maintenance tools
Communication Server 1000E
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Maintenance