This info. may be of little or no value to the OP
(as this is a older thread)…but hopefully it will be of some value to others.
A solid light or a fast blinking light indicates some type of drive activity and/or the fact that the drive is spinning. A slow blinking light is a good thing. It means that the drive is in “sleep” mode and isn’t spinning.
A constantly spinning portable drive is risky, as these type of drives weren’t intended for constant use! They tend to degrade much faster under these conditions. Not ideal for DVR purposes.
I believe that the WD “Elements” drives have no built in “sleep” function and therefore, will spin constantly (unless they’re being used with a computer or other device that can be completely powered off).
The WD “Passport/My Passport” portable drives have the built in “sleep” function. They will spin down when there’s no activity (after a pre- determined time) which makes them vastly superior if used with a Tablo!
Ideally, the WD “Elements” drives shouldn’t be recommended for use with a Tablo (due to potential longevity issues).