Figure 5 Power Subsystem Block Diagram
Two hot-swappable AC/dc power supplies generate main system power and standby power
voltage. One active power supply is sufficient to operate the system at maximum load. Each power
supply receives AC power through the integrated AC inlet. The system can operate at 180-264 V
AC and achieve 1+1 redundancy. The power supplies are power factor corrected and the maximum
dc power output of the power system is 1600 W. Service the hot-swappable power supplies by
sliding them out the rear of the chassis.
Power Button
The Power button on the server is a momentary contact push button. The BMC polls the front panel
Power button at a rate of at least 2 Hz. The Power button is an input to the System Power State
Management. If the system is off, a single button press will turn on the system. If the system has
booted to an OS, and a short button press is detected, a graceful-shutdown request will be sent
to the system by pulsing ACPI_PWR_BTN_L; when the ACPI bits are set to note the OS has shut
down, the BMC will perform a hard power down. If the system has not booted to an OS, or if a
long (5 second) button press is detected, the system will do an immediate hard power off.
System Power State Management
The system power may be controlled from the Power button, an IPMI Chassis command,
Wake-On-LAN, loss or gain of AC.
Applying System Power in normal customer usage, the server runs on 180 to 264V. Standby power
will be supplied on either; hence the BMC will power up when the power supplies are plugged
in. The BPS0_AC_OK and BPS1_AC_OK signals indicate whether the AC voltage to the power
supplies is within the required range. If neither BPS0_AC_OK nor BPS1_AC_OK is asserted, then
the BMC should log an event and prevent the system from turning on.
Procedure 1 Power On Sequence
1.
Update the cache of DIMM SPD information.
2.
Ensure that the memory board is detected and that the cpu board has a processor in socket
0. If these FRUs are not detected the BMC logs an event against the Missing Device sensor
(sensor 0x15).
Server Subsystems
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