Artesyn AXP1440, Installation And Use Manual, Page: 138 / 156

Shelf Management Alarm Module
136 AXP1440 Installation and Use (6806800H23U )
7.5.1.1 Voltage Sensors
On-board sensors provide the following power supply voltages. All voltage sensors are
implemented using the ADM1024 device on the master-only I
2
C bus. System management
software running on the SAM is responsible for reacting to an event when an interrupt is
triggered by the ADM1024 device.
7.5.1.2 Temperature Monitoring
An on-board temperature sensor is available on the SAM. This sensor is implemented through
the ADM1024.
7.5.1.3 Fan Speed and Control
All fan speed and fan voltage sensors are exposed on the active SAM.
The FTMs have 110 fan speed settings. The SAM uses a proprietary cooling algorithm to
automatically adjust the fan speed to cool the chassis based on sensor data from the blades as
well as inlet and outlet sensors on the FTMs. The minimum fan speed is 1.
In normal operating conditions, the cooling algorithm adjusts the fan speed based on the
ambient air temperature as measured at the inlet fans to maintain a
deltaT value (calculated
to be the rise in air temperature measured at the inlet and outlet fan sensors) based on the inlet
air temperature value. The lower the ambient temperature, the higher the rise in temperature
allowed.
At least one shelf manager must be in the shelf for proper operation of the cooling
algorithm. Removal of both shelf managers results in the fan speed remaining the same
and uncontrolled.