According to the Drobo knowledge base:
If your device is in standby mode, any of these situations could be occurring:
- a loss of connectivity to the host computer
- a loose data cable to the host computer
- the host computer is in sleep mode
From your question, it appears that the second and third possibilities don't apply. The first one may not seem to apply at first, but loss of connectivity between the external drive and the host computer can occur in several ways. The most likely cause is that Windows is shutting off the USB interface to which the Drobo is connected. Each USB port has its own independent settings for power management. Go to the Device Manager and check the settings for the USB port your drive is connected to. If you don't know which port it is, check (and possibly change) all of them.
- Press the Windows key + R.
- Type compmgmt.msc and press Enter.
- Click on Device Manager.
- Scroll down to USB devices.
- Right click on each USB Root Hub device and select Properties.
- Go to the Power Management tab and disable everything.