Kontron AT8242 - Manual (Page 95)

Thermal Considerations
79 AT8242
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6. Thermal Considerations
The following chapter provides system integrators with the necessary information to satisfy thermal and
airflow requirements when using the AT8242.
6.1 Thermal Monitoring
To ensure optimal operation and long-term reliability of the AT8242, all on-board components must remain
within the maximum temperature specifications. The most critical components on the AT8242 are the
network processors, the switch, the unit computer and the memory modules. Operating the AT8242 above
the maximum operating limits will result in application performance degradation (e.g. the network
processors might throttles if it overheats) or may even damage the board. To ensure functionality at the
maximum temperature, the blade supports several temperature monitoring and control features.
6.1.1 Heat Sinks
Multiple key components of the AT8242 are equipped with a specifically designed heat sink to ensure the
best possible product for operational stability and long-term reliability. The physical size, shape, and
construction of the heat sinks ensure the lowest possible thermal resistance. Moreover, the heat sinks were
specifically designed to use forced airflow as found in ATCA systems.
6.1.2 Temperature Sensors
The AT8242 is equipped with 17 temperature sensors that are accessible via IPMI. Sensors are precisely
positioned near critical components to accurately measure the on-board parts temperature. Temperature
monitoring must be exercised to ensure highest possible level of system thermal management. An external
system manager constitutes one of the best solution for thermal management, being able to report sensor
status to end-user or manage events filters for example.
All sensors available on the AT8242, and its RTM if present, are listed into the Sensor Data Repository with
their thresholds as defined by the PICMG 3.0 specification. The following extract (from the PICMG 3.0 Base
Specification) details naming convention for thresholds as well as the meaning of each threshold level.
IPMI non-critical / PICMG 3.0 minor / telco minor:
Temperature is getting closer to operating limit; it is not really a "problem" yet. It's only a warning.
IPMI critical / PICMG 3.0 major / telco major:
Temperature is at or over normal operating limit, but not in destructive zone. Unit still operating but
MTBF might be affected.