Kontron S5500 SEL Troubleshooting - Manual (Page 40)

System Event Log Troubleshooting Guide for Intel ® S5500/S3420 series Server Boards Cooling subsystem
Revision 1.0 Intel order number G74211-001 31
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 should the fan spin 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 for deassertion.