Specifications

7
Cisco 12016, Cisco 12416, and Cisco 12816 Router Clock and Scheduler, Switch Fabric, and Alarm Card Replacement Instructions
OL-13811-01
Alarm Card Overview
Monitoring Critical, Major, and Minor Alarm Status
The alarm card faceplate is equipped with three pairs of LEDs—labeled Critical, Major, and Minor—that
are used to identify system-level alarm conditions detected through the MBus.
Note The LEDs are paired for redundancy to protect against a single failed LED. The critical and major alarm
LED pairs are red; the minor alarm LED pair is yellow.
Because the two alarm cards in the router are redundant, a system alarm condition detected through the
MBus causes the same LEDs to be illuminated on both alarm cards.
The alarms can warn of an overheating condition on a component in one of the card cages, a blower
failure in a blower module, an over-current condition in a power supply, or an out-of-tolerance voltage
on one of the cards in one of the card cages. The LEDs are driven by the MBus software, which sets the
threshold levels for triggering the different stages of alarms.
The RP continuously polls the system for temperature, voltage, current, and blower speed values. If an
over-threshold value is detected, the RP sets the appropriate alarm severity level on the alarm card, which
lights one of the LED pairs and energizes the appropriate alarm card relays, activating any external
audible or visual alarms wired to the alarm card. The RP also logs a message about the threshold
violation on the system console.
Alarm Relay Contact Connection
The alarm card faceplate is equipped with a 25-pin D-sub connector that is tied directly to the critical,
major, and minor alarm relay contacts (normally open, normally closed, and common).
Note Only safety extra-low voltage (SELV) circuits can be connected to the connector labeled ALARM on the
alarm card faceplate. Maximum rating for the alarm circuit is 2A, 50 VA.
To comply with the intrabuilding lightning surge requirements of GR-1089-CORE, Issue II,
Revision 01, February 1999, you must use a shielded cable when connecting to the external alarm port
on the alarm card. The cable must consist of shielded cable terminated by shielded connectors on both
ends, with the cable shield material tied to both connectors.
The external alarm can be visual or audible. Audible external alarms can be silenced by pressing the
switch labeled ACO/LT (alarm cut-off/lamp test), on the alarm card faceplate. The ACO/LT switch 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. Visual alarms are reset by software.
Note Because the two alarm cards in the router are redundant, you can silence an audible alarm by pressing
the audible alarm reset switch on either alarm card.
The ACO/LT switch also can be used to verify that the alarm card LEDs are capable of lighting. If no
audible alarm is active, pressing the ACO/LT switch temporarily illuminates the LEDs on the alarm card
faceplate as a visual check that no alarm card LEDs have failed.