Specifications

2-4
Cisco IGX 8400 Series Provisioning Guide, Release 9.3.3 and Later Releases
OL-1166-04
Chapter 2 Cisco IGX 8400 Series Cards
Nodal Processor Module
NPM Failovers and Card Redundancy
In a nonredundant system, the NPM front card resides in either slot 1 or slot 2 (see the “Disabling NPM
Redundancy” section on page 2-4 for information on disabling NPM redundancy). In a redundant system
with two NPM front cards, the front cards reside in slot 1 and slot 2. A utility bus in the backplane
connects redundant NPMs.
Redundant NPMs have automatic failover, with the redundant card becoming active as soon as a failure
occurs on the primary NPM. The failed NPM will report an alarm condition through the fail LED on the
failed card’s faceplate.
In automatic failover, configuration and operational information changes are shared by both cards as
they occur.
Disabling NPM Redundancy
NPMs are shipped with NPM redundancy enabled.However, if you have only one NPM installed in your
chassis, your node will continue to report a minor alarm until you disable NPM redundancy on that node.
To disable NPM redundancy, use the following procedure.
Step 1 Log in to the IGX node at the SuperUser level.
Step 2 At the switch software CLI, disable NPM redundancy with the switch software cnfnodeparm 16 n
command.
Step 3 Log out of the IGX node.
System Clock Module Back Card
The system clock module (SCM) back card provides the main clock generation function for the IGX.
The SCM phase-locks internal IGX timing to the selected clock source for network synchronization. The
SCM also measures cabinet temperature and provides external interfaces for network management
access to the node.
Each SCM has the following external interfaces (see Figure 2-3):
• One 25-pin EIA/TIA-232 DCE control connector for terminal or PC access to the CLI
• One 25-pin EIA/TIA-232 DCE auxiliary connector with multiple configurable functions
• One 15-pin 802.3 LAN AUI connector for Telnet access to the CLI (for pin information, see
Table 2-3)
• One 15-pin external clock input connector to allow network synchronization signals from an
EIA/TIA-422 external clock source (external clock signals must be at either 1.544 or 2.048 MHz)
• One power supply monitor connector to measure power supply voltages and cabinet temperature
(for pin information, see Table 2-4)