Emerson AXP640-AC2-110VAC, Installation & Use Manual

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Shelf Management Alarm Module
AXP640 Installation and Use (6806800M24E)
147
7.5 Management and Control
This section gives a general description of the role of the on-board I
2
C devices and how
management, control, and redundancy is handled by the SAM. Detailed information on
sensors can be found in the
AXP1440/AXP1620 Subsystem IPMI Programmer’s Reference .
7.5.1 Hardware Monitoring and Control
The hardware monitoring and control functions implemented by the AXP640 are provided by
the on-board I
2
C-based devices.
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
There are two temperature sensors on the SAM. One for monitoring critical on-board
temperature and on for monitoring inlet air temperature.
7.5.1.3 Fan Speed and Control
All fan speed and fan voltage sensors are exposed on the active SAM.
The FTMs have 100 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 15.
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 sensors) based on the inlet air
temperature value. The lower the ambient temperature, the higher the rise in temperature
allowed.