System Overview 1-27
The power control logic performs these functions:
•
Controls power sequencing.
•
Monitors the combined output of power supplies and shuts down power if it is
not in range.
•
Monitors system temperature and powers down the system 30 seconds after it
detects that internal temperature of the system is above the value of the
environment variable over_temp. Default = 55
0
C.
•
Monitors the system and CPU fans at one second intervals and powers down the
system 30 seconds after it detects a fan failure.
•
Provides minimal visual indication of faults through LEDs.
•
Controls reset sequencing.
•
Provides I
2
C interface for fans, power supplies and temperature signals:
Power supply 0, 1: present
Power supply 0, 1: power OK
CPU fan 0, 1: OK
CPU 1: present
Overtemp: Temp OK
System fan 0, 1: OK
