Ambient Temperature Control; Server Management Summary; Server Board Management Controller - HP Carrier-grade cc2300 Product Manual

Figure 3-6. Fan Array with Four Fans Installed
The server comes in a non-redundant, four-fan configuration that consists of two 80-mm x 38-mm fans and
two 40-mm x 28-mm fans.
Air flows in through the front bezel over the peripheral bay and the hard drive bays, passes through the fans
and over the baseboard, and exhausts through the rear of the chassis. Each fan provides tachometer signal
output to the server baseboard to indicate a fan failure.
The cooling subsystem contains a fan array (see Figure 3-6) consisting of two 80-mm x 38-mm fans and two
40-mm x 28-mm fans to cool the server board and other components. A fan failure is indicated by one of the
fault LEDs located on the front panel.

Ambient Temperature Control

The server baseboard contains a Pulse-Width-Modulation (PWM) circuit, which cycles the 12-VDC fan
voltage to provide quiet operation when ambient temperature is low and no fan failures exist. There are 16
fan speed settings between 20°C and 35°C, with the lowest fan speed setting at 20°C or below. When the
room ambient temperature exceeds 35°C, the fan control circuit ceases cycling and delivers 12 VDC.
Following a room temperature excursion above 35°C the fan voltage does not reenter PWM mode until the
room temperature drops below 35°C and all fans are operational.

Server Management Summary

The baseboard server management architecture features a Baseboard Management Controller (BMC), which
autonomously monitors server status and provides the interface to server management control functions.
This controller is responsible for controlling system power, resets, monitoring voltages, temperatures, fans,
and communicating with secondary controllers on its Intelligent Platform Management Bus (IPMB).

Server Board Management Controller

The BMC on the system baseboard provides server management monitoring capabilities. A flash memory is
associated with the BMC that holds the operational code, Sensor Data Records (SDRs), and System Event
Log (SEL). There is also a serial EEPROM that holds the BMC configuration defaults and FRU information.
The various server management functions provided by the BMC are listed as follows:
•
Baseboard voltage monitoring
•
Fan failure detection
•
Fan speed control
•
Processor voltage monitoring
•
Processor presence detection
•
Processor Internal Error (IERR) monitoring
•
Fault Resilient Booting (FRB)
•
Processor disable control
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TP107
Chapter 3