I-Bus 0818D, User Manual

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Chapter 6 – Platform Management Option
0818D User’s Guide 6-9
The CMC firmware consists of the following main modules:
System Monitoring Software.
IPMI Command Interface Software.
I
²
C Controller Software.
6.6.1 System Monitoring Software
The System Monitoring software module executes on the CMC
board automatically on power up. It functions to continuously
monitor the environment of the system’s sensors, such as
temperature sensors, fan tachometers, voltage values, pushbuttons,
etc.
The types of sensors in the system are configured at the factory, and
stored in a non-volatile memory area of the board. Factory defaults
are compiled into the firmware image(s).
Note: Changes to the default Sensor Data Records (SDRs) when
made will not be persistent in the event of a failure of the CMC’s
EEPROM-based file system. If this should occur, the default SDRs
will be loaded.
Default sensors are defined in Table 6-1 “DEFAULT SDR
PARAMETERS” on page 6-10, and are incorporated in the firmware.
All sensor information must be interpreted after reading SDR data
from the CMC via IPMI commands. The SDR data required for
interpreting a sensor’s output is available via the
Get Sensor
Reading Factors command. The documentation for this command,
explaining how to perform the conversion, can be found in the I-Bus
Platform Management Programmer’s Guide.
CMC will log SEL (System Event Log) entries in the event of a
violation of a sensor threshold. This can be read by the host
controller by sending IPMI Command “Get SEL Entry.”
The threshold values for the installed sensors are configurable at any
time via the IPMI command interface. They are kept in a transient
configuration table in the CMC board. Default manufacturing
thresholds are defined in Table 6-1 and are incorporated in the
firmware.
Any violations of the thresholds will trigger alarm conditions (critical,
major, minor). Once a violation has triggered an alarm, the sensor
reading must satisfy the requirements of the hysteresis values for the
alarm condition to go away. These values refer to changes in raw