I use a the http interface that comes with the product. .

I just started a thread on the application I discussed in this thread. It is available for download from my web site as the Pronto Theater control application.
In that app is a library called RaidNAS that will answer all your questions. The main app makes a call to that library to spin the disks up and down.

In my Theater whenever the theater starts it spins the unraid disks up, and when I shut the theater down it spins down the drives.

The basic commands look something like:
Raid.SpinDown = "GET /update.htm?startState=STARTED&cmdSpinDownAll=Spin+Down HTTP/1.1\r\n\r\n"
Raid.SpinUp = "GET /update.htm?startState=STARTED&cmdSpinUpAll=Spin+Up HTTP/1.1\r\n\r\n";

but look at the library module