NEC N8100-1220F User Manual page 59

System Board Management Controller (BMC)
Server management is concentrated in the System Board Management Controller (BMC). The
BMC and associated circuitry are powered from a 5Vdc standby voltage, which remains active
when system power is switched off, but the ac power source is still on and connected.
The BMC supports the NEC DianaScope, which allows remote server management through
networks.
See Chapter 6 or online document in the NEC EXPRESSBUILDER CD-ROM for NEC
DianaScope.
One major function of the BMC is to autonomously monitor system management events, and log
their occurrence in the nonvolatile System Event Log (SEL). The events being monitored include
overtemperature and overvoltage conditions, fan failure, or chassis intrusion. To enable accurate
monitoring, the BMC maintains the nonvolatile Sensor Data Record (SDR), from which sensor
information can be retrieved. The BMC provides an ISA host interface to SDR sensor information,
so that software running on the server can poll and retrieve the server's current status.
The BMC performs the following:
Monitors server board temperature and voltage
Monitors processor presence and controls Fault Resilient Boot (FRB)
Detects and indicates fan failure
Manages the SEL interface
Manages the SDR Repository interface
Monitors the SDR/SEL timestamp clock
Monitors the system management watchdog timer
Monitors the periodic SMI timer
Monitors the event receiver
Controls secure mode, including video blanking, diskette write-protect monitoring, and
front panel lock/unlock initiation
Controls Wake On LAN via Magic Packet support.
General Description 2-21