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Relion 1900e/2900e Manual
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adapter is configured into the system. This enables easier usage of the fan speed control to support Intel as
well as third party chassis and better support of ambient temperatures higher than 35 ° C.
7.3.15 Power Management Bus (PMBus*)
The Power Management Bus (“PMBus*”) is an open standard protocol that is built upon the SMBus* 2.0
transport. It defines a means of communicating with power conversion and other devices using SMBus*-
based commands. A system must have PMBus*-compliant power supplies installed in order for the BMC or
ME to monitor them for status and/or power metering purposes.
For more information on PMBus*, please see the System Management Interface Forum Web site
http://www.powersig.org/.
7.3.16 Power Supply Dynamic Redundancy Sensor
The BMC supports redundant power subsystems and implements a Power Unit Redundancy sensor per
platform. A Power Unit Redundancy sensor is of sensor type Power Unit (09h) and reading type Availability
Status (0Bh). This sensor generates events when a power subsystem transitions between redundant and
non-redundant states, as determined by the number and health of the power subsystem’s component power
supplies. The BMC implements Dynamic Power Supply Redundancy status based upon current system load
requirements as well as total Power Supply capacity. This status is independent of the Cold Redundancy
status. This prevents the BMC from reporting Fully Redundant Power supplies when the load required by the
system exceeds half the power capability of all power supplies installed and operational. Dynamic
Redundancy detects this condition and generates the appropriate SEL event to notify the user of the
condition. Power supplies of different power ratings may be swapped in and out to adjust the power capacity
and the BMC will adjust the Redundancy status accordingly. The definition of redundancy is power
subsystem dependent and sometimes even configuration dependent.
This sensor is configured as a manual-rearm sensor in order to avoid the possibility of extraneous SEL events
that could occur under certain system configuration and workload conditions. The sensor shall rearm for the
following conditions:
•
PSU hot-add
• system reset
•
AC power cycle
• DC power cycle
System AC power is applied but on standby - Power unit redundancy is based on OEM SDR power unit
record and number of PSU present.
System is (DC) powered on - The BMC calculates Dynamic Power Supply Redundancy status based upon
current system load requirements as well as total Power Supply capacity.
The BMC allows redundancy to be configured on a per power-unit-redundancy sensor basis by means of the
OEM SDR records.
7.3.17 Component Fault LED Control
Several sets of component fault LEDs are supported on the server board. See Figure 3. Intel
®
Light Guided
Diagnostics - DIMM Fault LEDs and Figure 4. Intel ® Light Guided Diagnostic LED Identification. Some LEDs are
owned by the BMC and some by the BIOS.
The BMC owns control of the following FRU/fault LEDs:
Table 23. Component Fault LEDs