SEL Troubleshooting Guide

System Event Log Troubleshooting Guide for Intel
®
S5500/S3420 Series Server Boards Cooling Subsystem
Revision 1.1 Intel order number G74211-002 29
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 systems with hot-swap redundant fans.
5.1.1 Fan Speed Sensors
Fan speed 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 27: Fan Speed Sensors Typical Characteristics
Byte
Field
Description
11
Sensor Type
04h = Fan
12
Sensor Number
30h-39h (Chassis specific)
13
Event Direction and
Event Type
[7] Event direction
0b = Assertion Event
1b = Deassertion Event
[6:0] Event Type = 01h (Threshold)
14
Event Data 1
[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 28
15
Event Data 2
Reading that triggered event
16
Event Data 3
Threshold value that triggered event
The following table describes the severity of each of the event triggers for both assertion and deassertion.