Technical Product Specification

Intel® Server System R2000LH2/T2 Product Family TPS Power Subsystem
Revision 1.0
31
3.7.2
Powering on Cold Standby Supplies during a Fault or Over Current Condition
When an active power supply asserts its CR_BUS signal (pulling it low), all parallel power
supplies in cold standby mode shall power on within 100 μsec.
3.7.3
BMC Requirements
The BMC uses the Cold_Redundancy_Config command to define or configure the power
supply’s roll in cold redundancy and to turn on/off cold redundancy.
The BMC shall schedule a rolling change for which PSU is the Active, Cold Stby1, Cold Stby 2,
and Cold Stby 3 power supply. This allows for equal loading across power supply over their life.
Events that trigger a re-configuration of the power supplies using the Cold_Redundancy_Config
command:
 AC power ON
 PSON power ON
 Power Supply Failure
 Power supply inserted into system
3.7.4
Power Supply Turn On Function
Powering on and off of the cold standby power supplies is only controlled by each PSU sensing
the Vshare bus. Once a power supply turns on after crossing the enable threshold, it lowers its
threshold to the disable threshold. The system defines the position of each power supply in the
Cold Redundant operation. It will do this each time the system is powered on, a power supply
fails, or a power supply is added to the system.
The system is relied upon to tell each power supply where it resides in the Cold Redundancy
scheme.