Intel® Server Board S2600CW Family TPS
Intel® Server Board S2600CW Platform Management
Revision 2.4
77
By default the fans-off feature will be disabled. There is a BMC command and BIOS setup
option to enable/disable this feature.
The SmaRT/CLST system feature will also momentarily gate power to all the system fans to
reduce overall system power consumption in response to a power supply event (for example,
to ride out an AC power glitch). However, for this scenario, the fan power is gated by HW for
only 100ms, which should not be long enough to result in triggering a fan fault SEL event
5.3.14
Standard Fan Management
The BMC controls and monitors the system fans. Each fan is associated with a fan speed
sensor that detects fan failure and may also be associated with a fan presence sensor for
hot-swap support. For redundant fan configurations, the fan failure and presence status
determines the fan redundancy sensor state.
The system fans are divided into fan domains, each of which has a separate fan speed control
signal and a separate configurable fan control policy. A fan domain can have a set of
temperature and fan sensors associated with it. These are used to determine the current fan
domain state.
A fan domain has three states:
The sleep and boost states have fixed (but configurable through OEM SDRs) fan
speeds associated with them.
The nominal state has a variable speed determined by the fan domain policy. An OEM
SDR record is used to configure the fan domain policy.
The fan domain state is controlled by several factors. They are listed below in order of
precedence, high to low:
Boost
-
Associated fan is in a critical state or missing. The SDR describes which fan
domains are boosted in response to a fan failure or removal in each domain. If a
fan is removed when the system is in “Fans-off” mode, it will not be detected and
there will not be any fan boost till the system comes out of “Fans-off” mode.
-
Any associated temperature sensor is in a critical state. The SDR describes which
temperature-threshold violations cause fan boost for each fan domain.
-
The BMC is in firmware update mode, or the operational firmware is corrupted.
-
If any of the above conditions apply, the fans are set to a fixed boost state speed.
Nominal
-
A fan domain’s nominal fan speed can be configured as static (fixed value) or
controlled by the state of one or more associated temperature sensors.