Cisco GSR12/60 - 12012 Router -AnyLAN, SONET/SDH Installation And Configuration Manual page 52

Physical and Functional Overviews
The alarm card has three primary functions:
•
Provides a visual display of three severity levels of alarms (critical, major, and minor)
detected by the system through the MBus. The alarms can warn of an overtemperature
condition on a component in the card cage assembly, a fan failure in a blower module,
an overcurrent condition in a power supply, or an out-of-tolerance voltage on one of the
cards in the upper or lower card cage. The threshold levels for triggering the different
stages of alarms are set by software.
The RP continuously polls the system for temperature, voltage, current, and fan speed
values. If a threshold value is detected, the RP sets the appropriate severity level of
alarm on the alarm card lighting one of three pairs of LEDs and energizing the
appropriate alarm card relays activating any external audible or visual alarms.
•
Provides a connection point for the system to connect to two site-wide external alarm
systems. Two redundant, 25-pin D-sub connectors on the alarm card faceplate are tied
directly to the critical, major, and minor alarm relay normally open, normally closed,
and common contacts. Only safety extra-low voltage (SELV) external alarm circuits can
be attached to the two alarm card connectors. The external alarm can be visual or
audible. Audible external alarms can be reset by the reset switch on the alarm card
faceplate. Visual alarms are reset by software.
•
Provides visual status of the clock and scheduler cards and the switch fabric cards. Five
pairs of LEDs (one pair for each slot in the lower card cage) provide a visual status of
the switch fabric.
The alarm card faceplate contains the following connectors and indicators (see Figure 1-6):
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Critical/Major/Minor LEDs—Three pairs of LEDs; two pairs are red, and one pair is
amber. The LEDs are driven by MBus software. The LEDs give a visual indication of
critical, major, and minor alarms detected by the system. The LEDs are paired for
redundancy.
•
Audible alarm cutoff switch—A switch used to turn off an external audible alarm. It
does not affect any visual (LED) alarms set on the alarm card. The audible alarm
remains activated until the alarm condition is cleared or this button is pressed.
•
Alarm 1 and alarm 2 connectors—Two, 25-pin D-sub connectors. The alarm card relay
contacts are tied to these two connectors. You can attach visual and audible alarm
circuits to the alarm 1and alarm 2 connectors.
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