Generally detection of status information acts as any simple read command, causing that the idle-timer of the hard disk resets. So if the 'hard disk power down' timeout in Windows Power Management is set to higher than the Detection Frequency (on Configuration -> Advanced options page
in Hard Disk Sentinel) then the hard disk may never spin down.
If the hard disk can spin down, Hard Disk Sentinel automatically detects if the drive is in sleeping mode and does not wake up the drive(s) just to update the values. Then you may see the "Power state: sleeping" instead of "Power state: active" on the Information page.
The problem is that some disk controllers / drivers may not provide the power state for the software correctly. In this case (for example), the disk drive may be in sleeping state - but when Hard Disk Sentinel checks the power state, it seems active. The result is that the disk accessed (which spins up the drive). You may try to update the disk controller (motherboard chipset) drivers, as in many times the updated drivers can correct this behaviour.
Also you may try to adjust Configuration -> Advanced options -> Detection Frequency option to set Hard Disk Sentinel to access hard disk drives less frequently - as then disk drives can sleep down without problems.
You may also enable the "Automatic detection .based on disk utilization" option below that slider on the Configuration -> Advanced options page.
it checks if the hard disk really, actively used since the last detection: if the hard disk performed read/write commands (so not sleeping) then the drive status is detected - otherwise (if there was no activity) then the drive not accessed, allowing to enter and remain in sleep mode.
The use of this option may be good if
- you have many drives and most of them not always used
- you prefer to have your drives in sleeping state