QNAP TS-251B User Manual

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

QNAP TS-251B Specifications

General

RAID levels	0, 1, JBOD
RAID support	Yes
Storage drive size	- \
Storage drive capacity	- GB
Supported file systems	FAT32, HFS+, NTFS, exFAT, ext3, ext4
Storage drive interface	Serial ATA III
Storage drives installed	No
Storage drive sizes supported	2.5, 3.5 \
Supported storage drive types	HDD & SSD
Total installed storage capacity	0 TB
Number of storage drives installed	0
Number of storage drives supported	2
Stepping	B1
Tjunction	105 °C
Processor code	SR2Z8
Processor cache	2 MB
System bus rate	5 GT/s
Processor family	Intel® Celeron®
Processor socket	BGA 1296
Processor codename	Apollo Lake
Processor frequency	2 GHz
Processor cache type	Smart Cache
Processor lithography	14 nm
Processor manufacturer	Intel
Processor package size	24 x 31 mm
CPU configuration (max)	1
PCI Express slots version	2.0
Processor boost frequency	2.5 GHz
Processor operating modes	64-bit
PCI Express configurations	1x2+2x1, 4x1
Thermal Design Power (TDP)	10 W
On-board graphics card model	Intel® HD Graphics 500
Maximum internal memory supported by processor	8 GB
Flash memory	4096 MB
Internal memory	2 GB
Internal memory type	DDR3L
Ethernet LAN data rates	10, 100, 1000 Mbit/s
Supported network protocols	PPTP, L2TP/IPSec, OpenVPN
HDMI version	1.4b
USB 2.0 ports quantity	USB 2.0 ports have a data transmission speed of 480 Mbps, and are backwards compatible with USB 1.1 ports. You can connect all kinds of peripheral devices to them.
Chassis type	Tower
Cooling type	Active
Fan diameter	70 mm
Product color	White
LED indicators	HDD, LAN, Power, Status, USB
Number of fans	1 fan(s)
Cable lock slot type	Kensington
Type	NAS
Noise level	17.3 dB
Device class	Home & Home Office
Share folder	CIFS/SMB
Backup features	USB drive
Browser supported	Apple Safari 7 or later, Google Chrome, Microsoft Internet Explorer 10 or later, Mozilla Firefox
Security algorithms	256-bit AES, FIPS 140-2, HTTPS, SSH, SSL/TLS
AC input voltage	100 - 240 V
Power supply location	External
Power consumption (typical)	15.25 W
Power consumption (HDD standby)	8.08 W
Power supply unit (PSU) capacity	65 W
Operating temperature (T-T)	0 - 40 °C
Operating relative humidity (H-H)	5 - 95 %
Operating system version	4.3.4
Operating system installed	QNAP Turbo System
Mac operating systems supported	Mac OS X 10.10 Yosemite, Mac OS X 10.11 El Capitan, Mac OS X 10.12 Sierra, Mac OS X 10.13 High Sierra, Mac OS X 10.7 Lion, Mac OS X 10.8 Mountain Lion, Mac OS X 10.9 Mavericks
Server operating systems supported	Windows Server 2003, Windows Server 2003 x64, Windows Server 2008 R2, Windows Server 2008 R2 x64, Windows Server 2012, Windows Server 2012 R2, Windows Server 2012 R2 x64, Windows Server 2012 x64, Windows Server 2016, Windows Server 2016 x64
Windows operating systems supported	Windows 10, Windows 7, Windows 8
Cables included	AC, LAN (RJ-45)
Number of execution units	12
Maximum number of PCI Express lanes	6
Memory types supported by processor	DDR3L, LPDDR3-SDRAM, LPDDR4-SDRAM
Memory channels supported by processor	Dual
Intel Identity Protection Technology version	1.00
Intel Small Business Advantage (SBA) version	0.00
On-board graphics card base frequency	250 MHz
On-board graphics card burst frequency	700 MHz
Number of displays supported (on-board graphics)	3
Processor ARK ID	95597

Weight and Dimensions

Depth	226 mm
Width	105 mm
Height	168 mm
Weight	1530 g