HGST Ultrastar 7K4000 (SAS) Hard Disk Drive Specification
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Table 206: Power Conditions:
If the START STOP UNIT command is processed with the POWER CONDITION field set to ACTIVE, IDLE, or STANDBY,
then:
a) the logical unit shall transition to the specified power condition; and
b) the device server shall disable the idle condition timer if it is active and disable the standby condition timer if it is active
until another START STOP UNIT command is processed that returns control of the power condition to the logical unit, or a
logical unit reset occurs.
c) if under initiator control, the two minute floor and 60 head unloads per 24 hour period limits do not apply as they do when
under logical unit/timer control
If the START STOP UNIT command is processed with the POWER CONDITION field set to LU_CONTROL, then the
device server shall initialize and start all of the idle condition timers and standby condition timers that are supported and
enabled.
If the START STOP UNIT command is processed with the POWER CONDITION field set to LU_CONTROL, then the
device server shall enable the idle condition timer if it is active and disable the standby condition timer if it is active.
Power
Condition
Code
Name
Power
Condition
Modifier
Description
0h
START_VALID
0h Process the START bit
1h
ACTIVE
0h Place the device into the active power condition
2h
IDLE_A
0h Place the device into the idle-a power condition
2h
IDLE_B
1h Place the device into the idle-b power condition
2h
IDLE_C
2h Place the device into the idle-c power condition
3h
STANDBY_Z
0h Place the device into the standby_Z power condition
3h
STANDBY_Y
1h Place the device into the standby_Y power condition
4h
Reserved
0h Reserved
5h
Obsolete
0h-Fh Obsolete
6h
Reserved
0h Reserved
7h
LU_CONTROL
0h Transfer control of power conditions to the logical unit
8h - 9h
Reserved
0h Reserved
Ah
FORCE_IDLE_A
0h Force the idle_a condition timer to zero.
Ah
FORCE_IDLE_B
1h Force the idle_b condition timer to zero.
Ah
FORCE_IDLE_C
2h Force the idle_c condition timer to zero.
Bh
FORCE_STANDBY_Z
0h Force the standby_z condition timer to zero.
Bh
FORCE_STANDBY_Y
1h Force the standby_y condition timer to zero.
all Others
Reserved
0h Reserved