Cisco 7200 VXR router User Manual page 62

Functional Overview
For example, when you insert a port or service adapter, the longest pins make contact with
the port or service adapter first, and the shortest pins make contact last. The system
recognizes the signals and the sequence in which it receives them.
When you remove or insert a port or service adapter in a Cisco 7200 VXR router, the
midplane pins send signals to notify the system, which then performs as follows:
Rapidly scans the midplane for configuration changes.
1
Initializes all newly inserted port or service adapters, noting any removed interfaces and
2
placing them in the administratively shut down state.
3 Brings all previously configured interfaces on the port adapter back to the state they
were in when they were removed. Any newly inserted interfaces are put in the
administratively shut down state, as if they were present (but not configured) at boot
time. If a similar port adapter type is reinserted into a slot, its ports are configured and
brought on line up to the port count of the original port adapter. (A service adapter has
no configurable ports.)
Environmental Monitoring and Reporting Functions
Environmental monitoring and reporting functions are controlled by the network
processing engine and allow you to maintain normal system operation by identifying and
resolving adverse conditions prior to loss of operation. The environmental monitoring
functions constantly monitor the internal chassis air temperature and DC supply voltages
and currents. Each power supply monitors its own voltage and temperature and shuts itself
down if it detects a critical condition within the power supply. If conditions reach shutdown,
the system shuts down to avoid equipment damage from excessive heat. The reporting
functions periodically log the values of measured parameters so that you can retrieve them
for analysis later, and the reporting functions display warnings on the console if any of the
monitored parameters exceed defined thresholds.
Environmental Monitoring
The environmental monitoring functions use four sensors, two on the network processing
engine and two on the I/O controller, to monitor the temperature of the cooling air as it
moves through the chassis.
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