Nortel Circuit Card Installation Manual page 197

NT5D11 and NT5D14 Lineside T1 Interface cards
Note: Note: The STATUS LED indicates the enabled/disabled status of
both card slots of the lineside T1 card simultaneously. To properly enable
the card, both the motherboard and the daughterboard slots must be
enabled. The STATUS LED will turn off as soon as either one of the
lineside T1 card slots have been enabled. No LED operation will be
observed when the second card slot is enabled. To properly disable the
card, both card slots must be disabled. The LED will not turn on until
both card slots have been disabled.
The LED indicates that the lineside T1 card has detected an
RED ALARM
alarm condition from the T1 link. Alarm conditions can include such
conditions as not receiving a signal or the signal has exceeded bit error
thresholds or frame slip thresholds. See "Man-Machine T1 maintenance
interface software" on
If one of these alarm conditions is detected, this red LED will light. Yellow
alarm indication is sent to the far-end as long as the near-end remains in a red
alarm condition. Depending on how the Man-Machine Interface (MMI) is
configured, this LED remains lit until the following actions occur:
• If the "Self-Clearing" function has been enabled in the MMI, the LED
clears the alarm when the alarm condition is no longer detected. This is
the factory default.
• If the "Self-Clearing" function has not been enabled or it has been
subsequently disabled in the MMI, the LED will stay lit until the
command "Clear Alarm" has been typed in the MMI, even though the
carrier automatically returned to service when the alarm condition was
no longer detected.
The
YELLOW ALARM
yellow alarm signal from the terminal equipment side of the T1 link. See the
"Man-Machine T1 maintenance interface software" on
information on T1 link maintenance. If the terminal equipment detects a red
alarm condition, such as not receiving a signal or the signal has exceeded bit
error thresholds or frame slip thresholds, it can send a yellow alarm signal to
the lineside T1 card, depending on whether or not the terminal equipment
supports this feature. If a yellow alarm signal is detected, this LED will light.
The LED indicates if the lineside T1 card is fully operational because
MAINT
of certain maintenance commands being issued through the MMI. See
page 225 for information on T1 link maintenance.
LED indicates that the lineside T1 card has detected a
Circuit Card
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Description and Installation