Bueno Electric GPS-2-E-NTP Manual

GPS IRIG-B/NTP Time Server
GPS-2-E-NTP
June 01, 2013
Network Time Service GPS-2-E-NTP
www.buenoptic.com
Contents
1
2
3
4
5
6
7
Introduction......................................................................................................................... 3
Hardware............................................................................................................................. 4
Mounting GPS antenna....................................................................................................... 5
Powering up GPS-2-E-NTP................................................................................................ 6
NTP - Network Time Protocol ............................................................................................ 7
GPS-2-E-NTP software Setup ............................................................................................ 9
Technical specification...................................................................................................... 12
7.1 SYSTEM................................................................................................................ 12
7.2 HARDWARE......................................................................................................... 12
7.3 CASE ..................................................................................................................... 13
7.4 GPS ........................................................................................................................ 14
7.5 POWER ................................................................................................................. 14
7.6 ACCURACY ......................................................................................................... 14
7.7 OTHER .................................................................................................................. 14
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Introduction
The GPS-2-E-NTP Network Timeserver provides a high precision time directly to TCP/IP
networks using NTP (Network Time Protocol). It synchronizes time of any NTP clients
running on remote PC’s. It supports both NTP and SNTP clients for more of current popular
operating systems including: Microsoft Windows 95/98/Me/NT/2K/XP, Linux, FreeBSD,
IBM AIX and other UNIX family systems. It can synchronize simultaneously thousands of
servers, workstations and routers.
The high precision UTC time is powered by cesium atomic clocks coming via GPS (Global
Positioning System) satellite system. The independent GPS antenna can be connected optionally
too. Both antennas works redundant.
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The GPS-2-E-NTP distributes UTC reference time to 1 Ethernet 10/100Mbs sub-network. All
time and satellite information is traced on front panel 2 isolated LCDs. More detailed statistic is
available by remote NTP software: SNTP Manager for Microsoft Windows 2K/XP.
The installation of GPS-2-E-NTP timeserver is very easy. It simply requires basic TCP/IP
address (IP, MASK, GATEWAY) to be set up by ordinary terminal program (e.g. Windows Hyper
Terminal). This software can be executed on any remote PC connected to GPS-2-E-NTP via
Ethernet 10/100Mbs sub-network.
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Hardware
The GPS-2-E-NTP timeserver set includes:
• NTP timeserver unit (rack19 mounted 2U)
• GPS antenna with 30m. cable and frequency converter with built-in over voltage
protection
• CD with software utility and PDF manual
Timeserver unit is a multiprocessor system with 1 fast Ethernet 10/100Mbs interface. It is
design and manufactured without ventilators, fens or any other mechanical parts. Metal housing is
an important part of GPS-2-E-NTP cooling system but it is designed on a way that GPS-2-E-NTP
can be located in the neighborhood of any device working inside rack19 mount frame.
The 2 LCDs show GPS communication and timestamp information.
Figure 1: Front panel of GPS-2-E-NTP
BIT: Press it to delete the safe working days number.
DATE: Page up
SHOW: Page down & Return to main menu(Press 3 seconds). Press it to display Date, Work
days number, Longitude, Latitude, The time of switching on the device, Altitude…
POWER LOSS LED: Red light when 110-220V AC power is on, LED off while power off.
GPS LOSS LED: Red light is on while GPS source is off.
PPS LED: Blinks every second
Figure 2: Back panel of GPS-2-E-NTP
LAN connectors contains 4 LEDs: Red indicates cable connection, yellow one flashes
while data transmission.
On the back panel there is a power connection 110-240V AC, a power connection 24V
DC and GPS antenna rounded connector, 4 RS232-C connectors, a BNC connector for
IRIG-B, a group terminal block for pps, ppm, pph, RS485, RS422(IRIG-B), power loss alarm,
GPS loss alarm.
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Mounting GPS antenna
The GPS satellite time receiver has been designed to provide extremely precise time. High
precision available 24 hours a day around the whole world is the main feature of the new system
which receives its information from the satellites of the Global Positioning System. The Global
Positioning System (GPS) is a satellite-based radio-positioning, navigation, and time-transfer
system. The source of time is based on real cesium atomic clocks. Time is represented as UTC
(GMT).
GPS worldwide time propagation
The GPS satellites are not stationary but circle round the globe in a period of about 12 hours.
They can only be received if there is no building in the line-of-sight from the antenna to the
satellite, so the antenna unit must be installed in a location from which as much of the sky as
possible can be seen.
GPS antenna installation
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Powering up GPS-2-E-NTP
If both the GPS antenna and the power supply have been connected the system is ready to operate.
Besides that you are ready now to turn on the power.
About 120 seconds after power-up the receiver is warmed up and starts to operate with the
required accuracy. If the GPS receiver finds valid almanac and ephemeris data in its battery
buffered memory (and the receiver position has not changed significantly since its last operation)
the receiver can find out which satellites are in its view at that now. Only a single satellite needs to
be found to synchronize and generate output pulses, so synchronization can be achieved
maximally two minutes after the powerup.
After starting up the system the network function is initiated and the program for
communication between GPS and NTP becomes active. The following screen appear on LCDs
display while starting.
From the left side there are: time, date, error status.
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NTP - Network Time Protocol
Before you learn how to setup GPS-2-E-NTP, you also should read about what NTP itself.
NTP is a common method for time synchronization over networks. It is a protocol but a very
special one. The NTP is much different from any of known other communication protocols. It is
because NTP does not base on the principles of synchronizing machines to each other. It is based
on the principles of having all machines get as close as possible to the UTC time provided by
GPS-2-E-NTP. How it works?
GPS-2-E-NTP forms a statistic of delays and other data necessary to calculate local client
RTC offset. Knowing time difference the adjustment of the own RTC clock can be preceded
individually by each NTP client.
NTP works on a hierarchical model in which a small number of servers gives time to a large
number of clients. The clients on each level, or stratum, are in turn, potential servers to an even
larger number of clients on a higher numbered stratum. Stratum numbers increase from the
primary (stratum 1) servers to the lowest numbered strata at the bottom of the tree (stratum 15).
Clients can use time information from multiple servers to determine automatically the best source
of time and prevent wrong time sources from corrupting their own time.
For sure it may take several minutes (or even hours) to adjust a system time to the ultimate
degree of accuracy. There are several reasons for this. The most important one is that NTP
averages the results of several time exchanges in order to reduce the effects of variable latency.
This may take several minutes for NTP to even reach consensus on what the average latency is.
Generally it happens in about 5-10 minutes. In addition, it often takes several adjustments for NTP
to reach a synchronization. The result is that users should not expect NTP to immediately
synchronize two clocks. The ntp date command can be used if an instant synchronization is
needed.
The enterprise of GPS-2-E-NTP configuration includes following time sources:
• GPS 1.5GHz radio signal (worldwide)
• RTC internal quartz clock systems for backup
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Example of NTP stratum configuration in local LAN peer
A high precision synchronization is chosen by NTP automatically. The NTP always selects
best available source of time. Selection is based on several time references like: stratum level,
availability of timeserver, network delay, time difference, internal jitter factor etc.
NTP clients of GPS-2-E-NTP are referred to be a Stratum 2 clients. If they serve time to other
clients, they are also referred as Stratum 2 servers. The maximum NTP stratum number for a client
is 15.
NTP uses the UDP protocol on port 123 to communicate between clients and servers.
Attempts are tried at designated intervals until the server responds. The interval depends on a
number of factors and ranges from about once a minute to once every 17 minutes. Using UDP
prevents retries from using up network bandwidth if a time server with a large number of clients
goes down.The bandwidth requirements for NTP are also minimal.
Unencrypted NTP Ethernet packets are 90 bytes long (76 bytes long at the IP layer). A
broadcast server sends out a packet about every 64 seconds. A nonbroadcast client/server requires
2 packets per transaction. When the first starts, transactions occur about once per minute,
increasing gradually to once per 17 minutes under normal conditions. Poorly synchronized clients
will tend to poll more often than those well synchronized clients. Starting from NTP version 4
implementations, the minimum and maximum intervals can be extended beyond these limits, if
necessary.
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GPS-2-E-NTP software Setup
For the very first time of installation the GPS-2-E-NTP has to be configured by sub-network
remote terminal software. Please connect your sub-network cable to GPS-2-E-NTP. Other side of
cable please connects to any available computer with Windows.
Once terminal is connected the setup appears automatically (after clicking “Local
Search”
)on screen:
Main menu
To start configuration you shod first configure the LAN interface by simply placing IP,
MASK, DEFAULT GETEWAY for the Ethernet card.
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Setting the NTP Service
Setting
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Setting IP address, MASK address, GATEWAY address
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Technical specification
The GPS-2-E-NTP is high quality professional time server for computing, telecom, military and
other science purposes. It has been manufactured with no mechanical parts as coolers or hard disk.
All cooling system has been resolved on natural air circulation outgoing via metal case of unit.
7.1
SYSTEM
NTP - supports all versions of NTP, SNTP including latest release 4.1.1 supporting modes:
CLIENT, SERVER, BROADCAST, MULTICAST. Authentication: MD5 with
manual/automatic key generation.
SNTP - supports all versions of Simple Network Time Protocol
OS supports - Windows 95/98/Me/2K/XP/CE, OS/2, VAX-11/785 v4.3, HPUX, SunOS, Solaris,
MIPS Ultrix, ALPHA OSF/1, SGI IRIX, A/UX, AIX, Sinix, BSD, Linux, Dell SVR4, SCO
Unixware, CISCO products.
7.2
HARDWARE
ANTENNA – BNC connector
LAN - 3x RTL-8139 10/100 Based T: RJ-45 connector IEEE 802.3 - shielded data line
Serial Console – 9 way ‘D’ RS232,4800,N,8,1
IRIG-B – BNC connector
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Configuration of terminals on rear panel:
7.3
CASE
HAUSING - Metal desktop case, 2U
Front panel: 86mm high / 483mm wide
PROTECTION - rating IP20
DIMENSIONS - PHYSICAL DIMENSIONS: 483/86/286mm
LC DISPLAY - 6 character+8 character
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Network Time Service GPS-2-E-NTP
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GPS
CHIPSET - Motorola receiver (8) channel with RAIM
ANTENNA - BNC 1.5GHz / 8m + active converter (IP65 to UTP Cat 5. cable 200m. (max.
500m),
RECEIVER - input frequency 1575.42MHz (L1).
7.5
POWER
INPUT - 110-240V AC/DC(Main Power) or 24V DC(Redundancy Power)
FUSE - 1 electronic
OUTPUTS - +5V / 5A
TOTAL LOAD ≤15 Watt
7.6
ACCURACY
GPS - better than ±100 nsec after synchronization of first 1 hour
better than ±1 µsec during the first hour of operation
NTP - better than 10 msec (with nanosecond kernel)
7.7
OTHER
TEMPERATURE – 0~ 70℃
STORAGE - -40~ 125℃
HUMIDITY - 85% max.
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