Cisco XR 12404 - Manual (Page 46)

Chapter 1 Cisco XR 12404 Router Overview
Maintenance Bus
1-32
Cisco XR 12404 Router Installation Guide
OL-13830-02
Code Download
A portion of the line card operating software can be downloaded from the route
processor to the line card over the MBus. Because the MBus is relatively slow
compared to the CSF, only enough code is downloaded to the line card for it to
access the CSF and complete the download process.
Diagnostics
The diagnostic software image is downloaded from the route processor to the line
card during the test sequence.
Environmental Monitoring and Alarms
The MBus module on each component monitors that component’s environment as
follows.
• Line cards and the route processor are monitored for temperature by two
temperature sensors mounted on each card. The MBus module makes voltage
monitoring through software; for example the +2.5 VDC, +3.3 VDC, and
+5 VDC DC-to-DC converters.
• The CSF card is monitored for temperature by two temperature sensors
mounted on the card. The MBus module performs voltage monitoring through
software (for example, the +2.5 VDC and +3.3 VDC).
• Voltage monitoring the for +5 VDC, for example; is made by the alarm MBus
module on the CSF card.
• Environmental monitoring includes voltage and current monitoring,
temperature monitoring, and sensing for fan power and RPM.
todd.book Page 32 Monday, March 16, 2009 2:47 PM