Wake up external mybook 6TB connected to nas4free (Freebsd)

My external 6 TB mybook is connected to nas4free server. After one hour mybook harddisk spin down and the LED at front is blinking. I found no script to wake up the harddisk in mybook.
I need to wake up the harddisk before the rsync will start.
My actual solution is a reboot every night, so that rsync can backup the data from the server to mybook.
I dont want to do a rebbot every night by cron.
Has anyone a solution ?

Hello,

The Nas should wake up the my Book when it tries to run the rsync. If is not doing that, test the unit directly attached to a PC to see if there’s anything wrong with the unit.

Hello,

the NAS does not wake up mybook. I connected mybook to my PC and everything is ok.
I disabled the sleeptimer. Next night rsync was not successful.
Any other ideas ?