NEC NEAX Express, User Manual

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1-14 System Overview
System Board Management Controller (BMC)
All server management functionality 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.
One major function of the BMC is to autonomously monitor system management
events, and log their occurrence in the nonvolatile System Event Log (SEL). These
include events such as 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 software running on the
server can poll and retrieve the server's current status.
SEL contents can be retrieved after system failure, for analysis by field service
personnel using server management software tools such as Intel Server Control
available on the CD-ROM that ships with your system.
The BMC does the following:
„
Monitors server board temperature and voltage
„
Monitors processor presence and controls FRB
„
Detects and indicates baseboard fan failure
„
Manages the SEL interface
„
Monitors the system management watchdog timer
„
Monitors the periodic SMI timer
„
Manages front panel NMI handling
„
Monitors the event receiver
„
Manages the ISA host and IMB interface
„
Controls secure mode, including video blanking, floppy write-protect monitoring,
and front panel lock/unlock initiation
„
Manages the sensor event initialization agent
The BMC supports the Emergency Management Port (EMP) Console, which allows
remote server management via a modem or direct connection to a manager system.
Events monitored by the manager system include over-temperature and over-voltage
conditions, fan failure, or chassis intrusion.