Seagate manual ST9144 Family Installation Guide, Rev. B

14 ST9144 Family Installation Guide, Rev. B

Standby mode. The drive enters Standby mode when a Standby Immediate command is been received from the host. The drive can also enter Standby mode after a specifiable length of time has elapsed with the drive in Idle mode. The Standby timer is system-dependent, and is usually established by the user with a system utility such as Setup.

In Standby mode, the SeaCache buffer remains enabled, the heads are parked and the spindle is at rest. The drive accepts all commands, and returns to Active mode when disc access is necessary.

Sleep mode. The drive enters Sleep mode when a Sleep Imme- diate command is received from the host. The heads are parked and the spindle is at rest. The drive leaves Sleep mode when a hard or soft reset is sent from the host. After a soft reset is received, the drive exits Sleep mode with all current emula- tion/translation parameters intact.

Idle and standby timers. Default time delays for both the Idle timer and the Standby timer are set by the drive at power-on. These delays can also be specified by the user via the system Setup utility.

Each time the drive performs an Active function (read, write or seek) the Idle timer is re-initialized, and begins the countdown from the specified delay time to zero. If the Idle timer reaches zero before any drive activity is required, the drive transitions into Idle mode. Upon transitioning to Idle mode, the drive begins the Standby timer countdown. If the Standby timer reaches zero before any drive activity is required, the drive transitions into Standby mode. In both Idle and Standby mode the drive accepts all commands, and returns to Active mode when disc access is necessary.