spin down a USB-attached disk?

[Warren Block]

On Tue, 17 Sep 2013, Gary Jennejohn wrote:

> I have a possibly dumb question.  Is it possible to send a spindown
> command through USB to a SATA disk attached as umass?
>
> I like to spin down my disks before turning them off and with an ad-disk
> it's quite simple using camcontrol.
>
> I haven't been able figure how to do it through USB.

Can't camcontrol do the same thing, regardless of how the disk is 
attached?