LED
Status
Description
USB
Flashes blue every 0.5 sec
• A USB device (connected to the front USB port) is
detected.
• A USB device (connected to the front USB port) is
being removed from the NAS.
• A USB device (connected to the front USB port of the
NAS) is being accessed.
• Data is being copied to or from a USB or eSATA
device.
Blue
A USB device is detected in the front USB port.
Off
• No USB device is detected.
• The NAS has finished copying data to or from the USB
device connected to the front USB port.
Beep Alarm
Duration
Frequency
Description
Short beep (0.5 seconds) 1
• The NAS is starting up.
• The NAS is shutting down (software shutdown).
• The user pressed the Reset button.
• The operating system was updated.
3
The user tried to copy the NAS data to the external
storage device from the front USB port, but the data
cannot be copied.
Long beep (1.5 seconds) 3 (every 5 minutes)
The system fan is not functioning.
2
• The disk volume is about to reach its full
capacity.
• The disk volume has reached its full capacity.
• The drives are in degraded mode.
• The user started the drive rebuilding process.
• A drive is plugged in or out.
1
• The NAS was powered off by force shutdown
(hardware shutdown).
• The NAS was powered on successfully and is
ready.
TS-251B User Guide
Basic Operations
41