Meinberg LANTIME/GPS User manual

Technical Information
Operating Instructions
LANTIME / GPS
ETX 1HE

Contact Information
Meinberg Funkuhren GmbH & Co KG
Auf der Landwehr 22
D-31812 Bad Pyrmont
Telephone: [phone] / 9309-0
Telefax: +49 (0) 52 81 / 9309-30
Internet: http://www.meinberg.de
E-Mail: info meinberg.de
Bad Pyrmont, 7 Februar 2007

Table of Contents
Quick Start 8
Network Timeserver with GPS synchronized time base 9
The Modular System LANTIME 10
Supported Network Services 11
Additional Features and Options 12
User Interface 12
Options 12
Why to use a Network Timeserver 13
Network Time Protocol (NTP) 13
NTP Target 14
NTP-Client Installation 14
GPS satellite controlled clock 16
GPS167 Features 17
Time Zone and Daylight Saving 17
Mounting the GPS Antenna 18
Assembly with CN-UB/E 19
Antenna Short-Circuit 19
Booting the GPS receiver 20
Booting the Single Board Computer 20
Configuration User Interface 22
The Front Panel Layout 23
FAIL LED 23
LOCK LED 23
LC Display 23
MENU Key 23
CLR/ACK Key 23
NEXT Key 23
INC Key 23
Configuration via LC Display 24
The menus in Detail 25
Root Menu 25
Menu RECEIVER POS 26
Menu SV CONSTELLATION 26
Menu SV POSITION 27
Menu SETUP 27

SETUP LAN PARAMETERS 28
ENABLE OUTPUTS 28
SETUP TIME ZONE 29
SETUP DAYLIGHT SAV ON/OFF 30
SETUP SERIAL PORT 31
SETUP SERIAL STRING TYPE 31
SETUP IRIG SETTINGS (option) 32
SETUP INITIAL POSITION 33
SETUP INITIAL TIME 33
IGNORE LOCK 33
INITIATE COLD BOOT 34
INITIATE WARM BOOT 34
ANTENNA CABLE 34
Resetting Factory Defaults of the GPS 34
The LANTIME configuration interfaces 35
The WEB interface 36
Configuration: Main Menu 38
Configuration: Ethernet 39
Network interface specific configuration 41
IPv4 addresses and DHCP 41
IPv6 addresses and autoconf 41
High Availability Bonding 42
Additional Network Configuration 43
Configuration: Notification 44
Alarm events 45
E-mail messages 45
Windows Popup Messages 46
SNMP-TRAP messages 46
VP100/NET wall mount display 46
User defined Alarm scripts 47
NTP Client Monitoring 47
Alarm messages 48
Configuration: Security 49
Password 50
HTTP Access Control 50
SSH Secure Shell Login 51
Generate SSL Certificate for HTTPS 52
NTP keys and certificates 53
SNMP Parameter 53
Configuration: NTP 54
NTP Authentication 57
NTP AUTOKEY 59
Configuration: Local 62
Administrative functions 63

User Management 64
Administrative Information 65
Software Update 67
Automatic configuration check 68
Get Diagnostics Information 69
Web interface language 69
Configuration: Statistics 70
Statistical Information 71
Configuration: Manual 72
The Command Line Interface 74
CLI Ethernet 75
CLI Notification 78
Alarm events 78
E-mail messages 79
Windows Popup Messages 79
SNMP-TRAP messages 80
VP100/NET wall mount display 80
NTP Client Monitoring 81
CLI Security 82
Password 82
SSH Secure Shell Login 82
Generate SSL Certificate for HTTPS 83
NTP keys and certificates 83
CLI NTP Parameter 84
CLI NTP Authentication 85
CLI NTP Autokey 85
CLI Local 86
Administrative functions 86
User Management 87
Administrative information 87
Software Update 89
SNMP Support 90
Configuration over SNMP 92
Examples for the usage of the SNMP configuration features 93
Further configuration possibilities 94
Send special timeserver commands with SNMP 94
Configuration of the timeserver with SNMP: Reference 96
SNMP Traps 99
SNMP Trap Reference 100
Attachment: Technical Information 101

Skilled/Service-Personnel only: Replacing the Lithium Battery 101
Technical Specifications LANTIME Multipac 101
Safety instructions for building-in equipment 102
CE-Label 102
Rear Panel Connectors 103
SUB-D Connector Assignments 103
Time Sync Error Relay 104
Technical Specification 104
Rear View LANTIME 105
Technical Specifications GPS167 106
Accuracy of frequency TCXO quartz (standard) 107
Technical Specifications GPS167 Antenna 108
Signal Description GPS167 109
Rear Connector Pin Assignments GPS167 110
Technical Specifications LAN CPU 111
Rear Connector Pin Assignments LAN CPU 112
VGA, Keyboard Connector Pin Assignments 112
Technical Specifications Power Supply 113
Timecode (option) 114
Abstract 114
Principle of Operation 114
Block Diagram Timecode 114
IRIG Standard Format 115
AFNOR Standard Format 116
Assignment of CF Segment in IEEE1344 Code 117
Generated Time Codes 118
Selection of Generated Time Code 118
Outputs 119
AM - Sine Wave Output 119
PWM DC Output 119
Technical Data 119
USB Stick 120
Menu Structure 120
Menu Configuration Files 121
Menu Script Files 122
Keypad locking 122
Time Strings 123
Format of the Meinberg Standard Time String 123
Format of the GPS167 Capture String 124
Format of the SAT-Time String 125
Format of the Uni Erlangen String (NTP) 126

Format of the NMEA 0183 String (RMC) 128
Format of the ABB SPA Time String 129
Format of the COMPUTIME Time String 130
Menu Quick Reference 131
Declaration of Conformity 132
Manual VP100/NET Display configuration 133
Global Configuration File 135
Global Option File 136
Third party software 137
Operating System GNU/Linux 137
Samba 137
Network Time Protocol Version 4 (NTP) 138
mini_httpd 138
GNU General Public License (GPL) 139
Reference 143

Quick Start
- Approximately 30 seconds after power up the lower display line shows "NTP: not
sync" instead of "NTP: not ready"
SERVER NOT READY Wed, 18.11.1998
NTP: Not Ready UTC 10:03:30
==>
NORMAL OPERAT ON Wed, 18.11.1998
NTP: not sync UTC 10:04:10
- If the GPS receiver remains asynchronous (FAIL LED is still on after 12 minutes)
the number of satellites in view and the good satellites are to check (press
MENU twice) The antenna has to be installed without any obstructions to the
sky
SATELL TE CONSTELLAT ON
n view: 9 Good: 8 Sel: 3 19 26 13
- Enter TCP/IP address, netmask and default gateway:
- Press Menu four times to enter the LAN PARAMETERS setup menu
- Press CLR/ACK to see the TCP/IP address first
SETUP: LAN PARAMETERS
TCP/ P ADDRESS: DHCP 172.16.3.40
- Press CLR/ACK once again to be able to enter the IPv4 TCP/IP address
- With NEXT the respective digit is to select while INC is used to set the value
- To take over the changes it is necessary to press CLR/ACK again
- A wildcard '*' is displayed to confirm the changes
- Pressing NEXT, the netmask and the default gateway can be entered in the
same way
- Pressing MENU following by INC causes the changes to become active
Are you sure ? Press ...
NC -> YES MENU -> NO
NOTE: All settings are related to the first Ethernet connection (ETH0)
After this all further settings can be done via network interface, either by using a
WEB browser or a Telnet Session
Default user: root
Default password: timeserver
8

Network Timeserver with GPS synchronized time base
LANTIME (Local Area Network Timeserver) provides a high precision time base
to a TCP/IP network (Stratum-1-Server) The NTP (Network Time Protocol) is used
to synchronize all NTP clients with the reference The several LANTIME variants
differ from each other by the time reference A GPS receiver, a DCF77 receiver or an
IRIG time code receiver can be integrated as an internal reference as well as a
combination of these references (hybrid system) External references are also
possible LANTIME/GPS is a set of equipment composed of a satellite controlled
clock GPS167, a single-board computer with integrated network board and a power
supply, all installed in a metal 19" modular chassis and ready to operate A simplified
LINUX operating system is installed on the single-board computers flash disk Four
push buttons and a 2 x 40 character LC display can be used to configure and monitor
the time server After the network connection has been established the time server can
also be configured and monitored remotely from a workstation via TELNET or FTP
An integrated HTTP server enables access to the LANTIME by using an ordinary
WEB browser
9

The Modular System LANTIME
LANTIME is a set of equipment composed of a satellite controlled clock GPS167,
a single-board computer SBC GEODE 266 MHz with integrated network card, and a
power supply unit T60B, all installed in a metal desktop case and ready to operate
The interfaces provided by LANTIME are accessible via connectors in the rear panel
of the case Details of the components are described below
LOC K
C LR /A C K N EXT IN C
FA I L
M EN ULI GH T
LANTI ME
satellite controlled NTP time ser er
USB
Front View LANTIME/GPS
The implemented NTPD distributes the reference time from the GPS receiver cyclic
in the network Information on the NTPD is monitored on the LC display or can be
inquired via the network
The installation of LANTIME is very easy for the system/network administrator The
network address, the netmask and the default gateway have to be configured from the
front panel of LANTIME The network address or the equivalent name of LANTIME
has to be shown to all NTP clients in the TCP/IP network
As well as NTP the Linux system also supports a number of further network
protocols: HTTP(S), FTP, SSH and Telnet Because of this remote configuration or
status requests can come from any WEB browser This access via the network can be
deactivated Changes in the receiver status, errors or other important events are
logged either on the local Linux system or on an external SYSLOG-Server In
addition messages can be sent to a data center via SNMP traps or automatically
generated e-mails where they can be recorded Furthermore all alarm messages can be
displayed by the large display VP100/20/NET that is accessed via network
connection In order to avoid a service interruption several LANTIME NTP servers
can be installed in the same network to obtain redundancy
10

Supported Network Services
The following network services are provided via RJ45 10/100Base-T Ethernet (Auto
sensing):
- NTP v2, v3, v4
- NTP broadcast mode
- NTP multicast
- NTP symmetric keys
- NTP Autokey
- Simple Network Time Protocol (SNTP)
- TIME
- SNMP v1,2,3 with extended SNMP-Agent and SNMP-Traps for NTP and
reference clock status
- DHCP Client
- NFS
- TELNET
- FTP
- HTTP
- HTTPS with Openssl2
- SSH2 Secure Shell Login
- Alarm messages via e-mail
- IPv6
- 3 global IPv6 addresses configurable
- Autoconf Feature to be disabled
- supported network services: NTP, HTTP, HTTPS, SNMP, SSH
- Windows „net time“ via NETBIOS
- Winpopup (Window Mail)
11

Additional Features and Options
- external NTP timeserver
- free configuration of NTP: thereby MD5 authentication and access control via
address & mask restriction
- extended menu guidance for configuration and monitoring via Telnet, SSH or
serial terminal interface
- optional up to 3 RJ45/10/100 Mbit Ethernet interfaces
- extended HTTP statistic support with long-term graphic and access statistic to
NTP
- alarm messages can be displayed on external large display VP100/20/NET
- USB memory stick slot for extended functionality: software update, transfer of
secure certificates, log files and configurations, keypad locking
User Interface
- terminal connection via serial interface, status LED
- Web browser interface with graphical statistic of the one-day cycle offsets
- Telnet or Secure Shell Login for password protected operation of the Linux
operating system
- FTP access for updating the operating system and downloading log files
- Simple Network Management Protocol for automatically SNMP-Traps in case of
alarm
- SYSLOG messages can be passed to different computers
- configurable e-mail notification
- Simulation of a synchronous radio clock in order to operate without antenna
Options
- up to two further Ethernet RJ45 connectors
- Frequency and pulse outputs via BNC connectors (e g 10 MHz, 2 048 MHz, PPS)
- higher free running accuracy with optional oscillators (OCXO)
- IRIG-B outputs
- ANZ14/NET or VP100/20/NET as display connected via network
12

Why to use a Network Timeserver
A network timeserver should be used if accurate time is essential for undisturbed
operation It is possible to synchronize computers in a network using Public Domain
Time servers over the Internet, but there are good reasons not to use them:
- The possibility to send notification via e-mail or SNMP-Trap to an administrator
in the event of any synchronisation failure
- The computers in the network do not have a reliable internet connection
- The computers in the network cannot rely on the availability of external
timeservers Most operators of these timeservers do not guarantee continuous
availability nor the accuracy of their service
- NTP is able to compensate for the propagation delay of the network packets only
in case of “usual” internet traffic However, if unforeseen occurrences cause
badly fluctuating propagation times, it is possible that the time synchronisation
is disturbed Reasons for this may be: hacker attacks, numerous upcoming new
viruses etc
- An own timeserver cannot be easily compromised by external sources
Network Time Protocol (NTP)
NTP is a common method for synchronization of hardware clocks in local und
global networks The basic concept, version 1 [Mills88], was published in 1988 as
RFC (Request For Comments) Experiences made from the practical use in Internet
was followed by version 2 [Mills89] The software package NTP is an
implementation of the actual version 3 [Mills90], based on the specification RFC-
1305 from1990 (directory doc/NOTES) Permission to use, copy, modify and
distribute this software for any purpose and without fee is hereby granted (read File
COPYRIGHT)
NTP's way of operation is basically different from that of most other protocols NTP
does not synchronize all connected clocks, it forms a hierarchy of timeservers and
clients A level in this hierarchy is called a stratum, and Stratum-1 is the highest level
Timeservers of this level synchronize themselves by a reference time source, such as
a radio controlled clock, GPS-receiver or modem time distribution Stratum-1-Servers
distribute their time to several clients in the network which are called Stratum-2
A high precision synchronization is feasible because of the several time references
Every computer synchronizes itself by up to three valued time sources NTP enables
the comparison of the hardware times and the adjustment of the own clock A time
precision of 128 ms, often better than 50 ms, is possible
13

NTP Target
The software package NTP was tested on different UNIX systems Many UNIX
systems have pre-installed a NTP client Only some configurations have to be made
(/etc/ntp conf - see NTP Client Installation) NTP clients as freeware or shareware are
also available for the most other operating systems like Windows
XP/2000/NT/95/98/3x, OS2 or MAC The following WEB site is recommended to
get the latest version of NTP: "http://www eecis udel edu/~ntp/" More information
you can find on our web page at "http://www meinberg de/english/sw/ntp htm"
NTP-Client Installation
The following example shows the installation of a NTP client under UNIX First
make sure that there is no NTP installed on your computer because many UNIX
operating systems include NTP already
The shipped source code of the NTP daemon has to be compiled on the target system
Using the enclosed script file configures the compilation of the NTP daemon and all
tools
configure
All necessary information from the system will be collected and the corresponding
make files will be generated in the subdirectories
After that the NTP daemon and all needed utilities will be generated Therefore type:
make
While compiling the NTP daemon several warnings may appear These warnings are
mostly unimportant In case of problems during the compilation read the system
dependent notes in the subdirectory ‘html’
Afterwards the generated programs and tools have to be moved in the corresponding
directories Therefore type:
make install
The time adjustment can occur in different ways Either the system time can be set
once by using the tool "ntpdate lantime" or the NTPD daemon is started In the first
case it is recommended to set the time automatically with "cron" or once when
booting the system The second case is described below
First a file named /etc/ntp conf has to be generated with an editor Adapting the file to
Meinberg LANTIME it should contain the following:
# Example for /etc/ntp.conf for Meinberg LANTIME
server 1 7.1 7.1.0 # local clock
server 17 .16.3.35 # TCPIP address of LANTIME
# optional: Driftfile
# driftfile /etc/ntp.drift
# optional: activate all messages in syslogfile
# logconfig =all
14

The NTP daemon is started with "ntpd" or, using "rc local", while booting the system
Status messages during operation are saved in /var/adm/messages and /
var/adm/syslog (corresponding to the syslog configuration)
e.g.: tail /var/log/messages
shows the last lines from the file "messages"
The status messages can also be redirected in a log file by using the following option:
ntpd -llogfile
The command "ntpq" in the directory "ntpq" requests the actual status of the NTP
daemon (see also doc/ntpq 8)
e.g.: ntpq/ntpq
An interpreter appears; Type "?" for a list of all available commands The command
"peer" is used to list all active reference clocks:
remote refid st t when poll reach delay offset jitter
================================================================================
LOCAL(0) LOCAL(0) 3 l 36 64 3 0 00 0 000 7885
lantime GPS 0 l 36 64 1 0 00 60 1 15875
with the following meaning:
- remote: list of all valid time servers (ntp conf)
- refid: reference number
- st: actual stratum value (hierarchy level)
- when: last request (seconds)
- poll: period of requesting the time server (seconds)
- reach: octal notation of the successful requests, shifted left
- delay: delay of the network transmission (milliseconds)
- offset: difference between system time and reference time
(milliseconds)
- jitter: variance of the offsets (milliseconds)
Repeatedly "peer" commands lets the user observe the accuracy of the NTP daemon
Every 64 seconds (value of -poll) a new time string is red in from the radio clock The
NTP daemon needs approx 3 5 minutes for initialisation This is indicated by a
wildcard (*) on the left side of the remote name
The NTP daemon terminates itself if the system time differs from the UTC time by
more than 1024 seconds This often happens when the time zone is not correctly set
(see also system manual "zic" or "man zic")
15

GPS satellite controlled clock
A Meinberg GPS167 satellite controlled radio clock is used as a reference time
base The satellite receiver clock GPS167 has been designed to provide extremely
precise time to its user The clock has been developed for applications where
conventional radio controlled clocks can not meet the growing requirements in
precision 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 It was installed by the United States Department
of Defence and provides two levels of accuracy: The Standard Positioning Service
(SPS) and the Precise Positioning Service (PPS) While PPS is encrypted and only
available for authorized (military) users, SPS has been made available to the general
public
GPS is based on accurately measuring the propagation time of signals transmitted
from satellites to the user’s receiver A nominal constellation of 21 satellites together
with 3 active spares in six orbital planes 20000 km over ground provides a minimum
of four satellites to be in view 24 hours a day at every point of the globe Four
satellites need to be received simultaneously if both receiver position (x, y, z) and
receiver clock offset from GPS system time must be computed All the satellites are
monitored by control stations which determine the exact orbit parameters as well as
the clock offset of the satellites' on-board atomic clocks These parameters are
uploaded to the satellites and become part of a navigation message which is
retransmitted by the satellites in order to pass that information to the user’s receiver
The high precision orbit parameters of a satellite are called ephemeris parameters
whereas a reduced precision subset of the ephemeris parameters is called a satellite’s
almanac While ephemeris parameters must be evaluated to compute the receiver’s
position and clock offset, almanac parameters are used to check which satellites are in
view from a given receiver position at a given time Each satellite transmits its own
set of ephemeris parameters and almanac parameters of all existing satellites
16

GPS167 Features
The hardware of GPS167 is a 100 mm x 160 mm microprocessor board The front
panel integrates a 2 x 40 character LC display, two LED indicators and 5 push
buttons The receiver is connected to the antenna/converter unit by a 50 Ω coaxial
cable (refer to "Mounting the Antenna") Feeding the antenna/converter occurs DC
insulated via the antenna cable Optionally an antenna splitter for up to four receivers
connected to one antenna is available
The navigation message coming in from the satellites is decoded by GPS167´s
microprocessor in order to track the GPS system time with an accuracy of better than
500 ns or 250 nsec (OCXO) Compensation of the RF signal’s propagation delay is
done by automatic determination of the receiver’s position on the globe A correction
value computed from the satellites´ navigation messages increases the accuracy of the
board’s TCXO or OCXO to 10-9 and automatically compensates the oscillators aging
The last recent value is restored from the battery buffered memory at power-up
Time Zone and Daylight Saving
GPS system time differs from the universal time scale (UTC) by the number of leap
seconds which have been inserted into the UTC time scale after GPS had been
initiated in 1980 The current number of leap seconds is part of the navigation
message supplied by the satellites, so GPS167´s internal real time is based on UTC
Conversion to local time including handling of daylight saving year by year can be
done by the receiver’s microprocessor if the corresponding parameters are set up by
the GPS Monitor (included Windows software)
Internally LANTIME always runs on UTC based time NTP calculates this UTC time
from the GPS receivers local time The time zone of LANTIME is fixed to UTC
However, the time monitored on the LC display is the GPS receiver's local time
17

Mounting the GPS Antenna
The GPS satellites are not stationary but circle round the globe in a period of about
12 hours They can only be received if no building is in the line-of-sight from the
antenna to the satellite, so the antenna/converter unit must be installed in a location
from which as much of the sky as possible can be seen The best reception is given
when the antenna has a free view of 8° angular elevation above the horizon If this is
not possible the antenna should be installed with a mostly free view to the equator
because of the satellite courses which are located between latitudes of 55° North and
55° South If this is not possible problems occur especially when at least four
satellites for positioning have to be found
The antenna/converter unit can be mounted on a pole with a diameter up to 60 mm or
on a wall A 50 cm plastic tube, two holders for wall-mounting and clamps for pole-
mounting are added to every GPS167 A standard coaxial cable with 50 Ω impedance
should be used to connect the antenna/converter unit to the receiver The maximum
length of cable between antenna and receiver depends on the attenuation factor of the
used coaxial cable
Example:
Up to four GPS167 receivers can be run with one antenna/converter unit by using the
optional antenna splitter The total length of one antenna line between antenna,
splitter and receiver must not be longer than the max length shown in the table above
The position of the splitter in the antenna line does not matter When installing the
high voltage protector CN-UB/E (CN-UB-280DC) be aware to set it directly after
reaching indoor The CN-UB/E is not for outdoor usage
18
Type of cable diameter
Ø [mm]
Attenuation at 100MHz
[dB]/100m
max lenght
[m]
RG58/CU 5mm 15 9 300 1
RG213 10 5mm 6 9 700 1
1)This specifications are made for antenna/converter units produced after January, 2005
The values are typically ones; the exact ones are to find out from the data sheet of the
used cable

Assembly with CN-UB/E
Type N / BNC
male
Type N
male
Type N
male
CN-UB/E
1.5m max.
Type N
male
GPS167
Antenna
Meinberg
GPS
As short as possible!
Antenna Short-Circuit
In case of an antenna line short-circuit the following message appears in the
display:
ANTENNA SHORT-C RCU T
D SCONNECT POWER !!!
If this message appears the clock has to be disconnected from the mains and the
defect eliminated After that the clock can be powered-up again The antenna supply
voltage must be in a range of 18 5 VDC (no load) and 17 VDC (connected GPS
antenna)
19

Booting the GPS receiver
If both, the antenna and the power supply, have been connected the system is ready
to operate About 10 seconds after power-up the receiver’s oscillator has warmed up
and operates with the required accuracy If the receiver finds valid almanac and
ephemeris data in its battery buffered memory and the receiver’s position has not
changed significantly since its last operation the receiver can find out which satellites
are in view now Only a single satellite needs to be received to synchronize and
generate output pulses, so synchronization can be achieved maximally one minute
after power-up
SERVER NOT READY Wed, 18.11.1998
NTP: Not Ready MEZ 10:04:10
If the receiver position has changed by some hundred kilometres since last operation,
the satellites´ real elevation and Doppler might not match those values expected by
the receiver thus forcing the receiver to start scanning for satellites This mode is
called Warm Boot because the receiver can obtain ID numbers of existing satellites
from the valid almanac When the receiver has found four satellites in view it can
update its new position and switch to Normal Operation If the almanac has been
lost because the battery had been disconnected the receiver has to scan for a satellite
and read in the current almanacs This mode is called Cold Boot It takes 12 minutes
until the new almanac is complete and the system switches to Warm Boot mode
scanning for other satellites
Booting the Single Board Computer
The LINUX operating system is loaded from a packed file on the flash disk of the
single board computer to a RAM disk All files of the flash disk are stored in the
RAM disk after booting Because of that it is guaranteed that the file system is in a
defined condition after restart This boot process takes approx one minute During
this time the following message appears on the display:
GPS: NORMAL OPERAT ON Wed, 18.11.2002
NTP: Not Ready MEZ 10:04:10
After starting up the LINUX system the network function is initiated and the program
for communication with the GPS and the NTPD (NTP daemon) is started After that
NTPD starts synchronisation with the reference clocks (usual the hardware clock of
the single board computer and the GPS receiver) Until synchronisation is finished the
following message is displayed:
GPS: NORMAL OPERAT ON Wed, 18.11.2002
NTP: Not Sync MEZ 10:04:10
20