How to Keep drives spinning

[ShiamakD']

I have found that the drives are programmed to spin down if inactive and even if they are kept with the head disconnected and this is making things difficult while using brushless DC spindle motors, so here I just wanted to know if there is a way in which I can keep drives spinning indefinitely?? Is there anyone who is aware of any such command??

[Bebo.K]

Even I need some help regarding the same actually I am having a Seagate 7200.7 over the serial console and I have been trying out some partial command set but then when I execute certain commands then I get an error message saying "Command inactive - no valid cert code detected", I don’t know what that means, anyone has an idea about the same??