System Event Log Troubleshooting Guide for EPSD
 
Platforms Based on Intel
®
 Xeon
®
 Processor E5 4600/2600/2400/1600/1400 Product Families 
Cooling Subsystem 
Revision 1.1  Intel order number G90620-002  45 
5.  Cooling Subsystem 
5.1  Fan Sensors 
There are three types of fan sensors that can be present on Intel
®
 Server Systems: speed, presence, and redundancy. The last two 
are only present in the systems with hot-swap redundant fans. 
5.1.1  Fan Tachometer Sensors 
Fan tachometer sensors monitor the rpm signal on the relevant fan headers on the platform. Fan speed sensors are threshold-based 
sensors. Usually they only have lower (critical) thresholds set, so that a SEL entry is only generated if the fan spins too slowly. 
Table 29: Fan Tachometer Sensors Typical Characteristics 
30h-3Fh (Chassis specific) 
BAh-BFh (Chassis specific) 
Event Direction and 
Event Type 
[7] Event direction 
0b = Assertion Event 
1b = Deassertion Event 
[6:0] Event Type = 01h (Threshold) 
[7:6] – 01b = Trigger reading in Event Data 2 
[5:4] – 01b = Trigger threshold in Event Data 3 
[3:0] – Event Trigger Offset as described in Table 30 
Reading that triggered event 
Threshold value that triggered event 
The following table describes the severity of each of the event triggers for both assertion and deassertion.