Specifications

6
Cisco 12016, Cisco 12416, and Cisco 12816 Router Clock and Scheduler, Switch Fabric, and Alarm Card Replacement Instructions
OL-13811-01
Alarm Card Overview
The second CSC in the router provides data path, scheduler, and reference clock redundancy. The
interfaces between the line cards and the switch fabric are monitored constantly. If the system detects a
loss of synchronization (LOS), it automatically activates the data paths of the redundant CSC, and data
flows across the redundant path. The switch to the redundant CSC occurs within sub-seconds (the actual
switch time depends on your configuration and its scale).
Switch Fabric Card Cage Status LEDs
Status LEDs for all cards installed in the switch fabric card cage are located on the alarm card. There are
no status LEDs on the CSC or SFC. The alarm card has one pair of LEDs for each of the five card slots
in the switch fabric card cage. See the following section (Alarm Card Overview) for more information.
Alarm Card Overview
The router is equipped with two alarm cards. One card occupies the dedicated far left slot of the upper
card cage. A second alarm card occupies the dedicated far right slot of the lower card cage. In both card
cages, the alarm card slot differs from the rest of the card cage slots. It is labeled as an alarm card slot,
it comes with a pre-installed alarm card, and it has a different backplane connector than other cards
(Figure 2.)
Figure 2 Alarm Card (Front View)
The router alarm card has three primary functions:
1. Provides a visual display of three severity levels of alarms (critical, major, and minor) detected by
the system through the maintenance bus (MBus).
2. Provides a connection to a site-wide external alarm system.
3. Provides visual indicators of the status of the alarm card, CSCs, and SFCs.
ACO/LT
ALARM
CSC
0
FAI L
1
0
1
2
ENABLED
ENABLED
FAI L
CRITICAL
MAJOR
MINOR
SFC
ALARM
26867
Pin 25
Audio alarm
cutoff switch
Pin 1
Handle
Critical, major, and
minor alarm LEDs
Clock and scheduler card
and switch fabric card LEDs
ENABLED
FAIL
CSC
0
FAIL
1
0
1
2
ENABLED
CRITICAL
MAJOR
MINOR
SFC