EW9955A/AR— NTP Server with GPS common view—
E3 Design, Inc.

Network Time Server / EW9955A/ARIntroduction

Neortw

EW9955A/AR is Stratum 1 Network Time Server that use GPS as a time synchronization source. It provide
secure, accurate, and reliable time inside your domain. It always synchronize to national time and frequency
standard of NICT via GPS satellites using the GPS commonview method. So user can easily achieve precise

imFeatures

kT

time-transfer at out-of-the-way place with an accuracy of approximately ±20ns.

eS• Precise time and frequency transfer using the GPS common-view method.

er• Easy to synchronize to the UTC(NICT) - National Institute of Communication Technology, Japan timeveand frequency standard.

rE• Easy to achieve Stratum 1 NTP server. (Built-in software NTP function)• High performance hardware-SNTP server option (EB9964) is available. (1000,000 ntp request/sec)

55
99W• Compact 1U size - EIA 19 inches rack mountable.

• EW9955A/AR is developed under technology license from NICT (National Institute of Communication
Technology, Japan).

ARA/
図 1: EW9955A/AR front view

Network Time Server / EW9955A/AR

EW9955A/AR specification
Description

NeSection ParameterGPS receiver function
Receiver type
Channels
GPS antenna powerkT

NTP server function
hardwareOperation System
ntpd version
PerformanceortwAcquisition
Sensitivity

L1 frequency, C/A Code32 Channels, 8192 time/frequency search windows+5V ± 5%/100mA(max), +3.3V ± 5%/50mA(max)(Software setting)
Cold Start: 28s, Warm Start: 28s, Hot Start: 1s
T racking : −162dBm, Reacquisition : −160dBm, ColdStarts : −148dBm

imer

3 × 10−11 /s, 1 × 10−11 /10s, 3 × 10−12 /100s
2 × 10−12 /day, 3 × 10−11 /month (typical)
12min−75dBc/Hz at 1Hz, −89dBc/Hz at 10Hz, −128dBc/Hz at 100Hz, −140dBc/Hz
at 1kHz−80dBcverE

Rubidium time source(EW9955AR only)
Short term stability
Long term stability
Warm-up time
Phase noise
Sprious

GGTTS format version 1
http://tb.nict.go.jp/ (default)
σ 10ns (standard deviation)±60nS(max)eSTime transfer function
Data exchange format
GGTTS data source
Syncronization to UTC
1pps accuracy

CPU: Intel N270 / Memory: 2Gbyte / SSD: 120Gbyte
Linux, Kernel 3.2.65-pps01-rt94
4.2.8p2 (http://www.ntp.org)
5000 requests/s

5 × 10−11 /sec(T ypical)±0.7ppm(1st year)、 ±4.0ppm(10years)
60sec−100dBc/Hz at 10Hz, −130dBc/Hz at 100Hz, −140dBc/Hz at 1kHz

Input/Output
1PPS IN
1PPS OUT
10MHz OUT
IRIG-B OUT
GPS ANT IN
GPS 1PPS OUT
1PPS COM OUT
LCD display
LED display
Expansion slot

SMA × 1 / 5V-TTL, 50Ω (50Ω with/without termination)
SMA × 2 / 5V-TTL, 50Ω, 100µs
SMA × 1 / 5V-TTL, 50Ω
SMA × 1 / 5V-TTL, 50Ω, software selectable on 1PPS OUT2 port.
SMA × 1
SMA × 1 / 5V-TTL, 50Ω (GPS module raw output), 100µs
D-Sub9(F) × 1 / (external 1PPS output.RS-232C(DCD)
status, localtime, number of GPS satellites, etc.
Internal PPS, External 1PPS, Rb lock status, etc.
Half-size PCI × 1

Log/GGTTS diﬀ file store
Geodetic systems
Measuring schedule
GGTTS data store
GGTTS diﬀ data store
15s log
1s logerror log
info log

WGS-84
built-in BIPM common-view schedule
2 weeks(default)
2 weeks(default)
2 weeks(default)2 weeks(default)
2 weeks(default)
2 weeks(default)

55
99W

OCXO time source(EW9955A and AR)
Short term stability
Long term aging
Warm-up time
Phase noiseAR
A/note1 note2

1 The performance will be achieved with at least 5 GPS satellites.
2 In accordance with out policy of continuous improvement, we reserve the right to modify the specification of product without
prior notice.

Network Time Server / EW9955A/AR

EW9955A/AR Specification
Parameter

Description

NeSection
Power

Supply Voltage
Input power

tw

AC100V..AC240V(50Hz/60Hz)
80W(max) (EW9955AR)
60W(max) (EW9955A)

Size
Weight431.5mm(W ) × 431.5mm(D) × 43.0mm(H)19 inches EIA rack mount 1U size.
6.5kg(EW9955AR)
6.3kg(EW9955A)

im

AC100V 2mveereS

Accessories
AC cablekT

Physical+10.. + 40 ◦ C
10%..80%

orOperating environmental
Temperature
Humidity

rE
55
99W
ARA/

図 2: Rear view

Network Time Server / EW9955A/AR

EW9955A/AR Options

twNe

SectionParameter
GPS antenna
EW9955-20
Novatel/GPS701GG
EW9955-21
Trimble/BULLET III
Hardware SNTP server board
EW9964-WS

Description
http://www.novatel.com/assets/Documents/Papers/GPS701 702GG.pdf
http://trl.trimble.com/docushare/dsweb/Get/Document-8420/(Recommended)
EB9964 Hardware SNTP board with Web interface software.

2−28−3 Sekimachi−Kita, Nerima−ku,
TOKYO 177−0051, JAPAN
Phone: +81−3−6279−7802 / Fax: +81−3−6279−7803

rE

URL: http://www.e3design.jp / MAIL: sales@e3design.jp

veer

Martell House 2F,eS

E3 Design, Inc.

imkTorContuct Information

5599W
ARA/2013/07/23 rev 1.0E