Meinberg LANTIME M600 MRS User manual

MANUAL
LANTIME M600 MRS
Multi Reference Source NTP Server
31st July 2014
Meinberg Radio Clocks GmbH & Co. KG

Table of Contents
1 Impressum 1
2 Quick Start 2
3 Network Timeserver synchronized by multiple reference time sources 4
4 The Modular System LANTIME 5
4.1 SupportedNetworkServices...................................... 6
4.2 AdditionalFeatures .......................................... 6
4.3 UserInterface ............................................. 6
4.4 InputandOutputOptions....................................... 7
4.5 Why to use a Network Time Server? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
5 Network Time Protocol (NTP) 8
5.1 NTPTarget .............................................. 8
5.2 NTP-ClientInstallation ........................................ 8
6 GPS satellite controlled clock with MRS option 10
6.1 MRSfunctionality........................................... 10
6.2 GPSfunctionality ........................................... 12
6.3 GPSClockFeatures.......................................... 12
6.4 Time Zone and Daylight Saving . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
7 Mounting the GPS Antenna 13
7.1 Example:................................................ 13
7.2 Antenna Assembly with Surge Voltage Protection . . . . . . . . . . . . . . . . . . . . . . . . . . 14
7.3 AntennaShort-Circuit......................................... 15
8 Booting the GPS170 receiver 16
9 Booting the Single Board Computer 17
10 Configuration User Interface 18
10.1 Introduction: Conguration LANTIME . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
10.2 Description of the graphical menu- VF- Display . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
10.3ThemenusinDetail.......................................... 23
10.4Menu:ReferenceTime ........................................ 25
10.4.1MenuSetupMRS....................................... 25
10.4.2 Menu IRIG Input Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
10.4.3InfoGPSReceiver....................................... 29
10.4.4GPSReceiverPosition .................................... 29
10.4.5 GPS Satellite Constellation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
10.4.6GPSStatusandVersion.................................... 30
10.4.7 Setup GPS Receiver Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
10.4.8InitGPSReceiver....................................... 30
10.4.9InitReceiverPosition ..................................... 30
10.4.10InitReceiverTime....................................... 31
10.4.11Initiate Cold Boot of GPS Receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
10.4.12Initiate Warm Boot of GPS Receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
10.4.13Set Antenna Cable Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
10.4.14Set GPS Receiver Simulation Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
10.4.15SetupGPSOutputs...................................... 33
10.4.16EnableOutputs ........................................ 33
10.4.17SetupSerialOutputs ..................................... 34
0

10.4.18SetupTimeZone ....................................... 35
10.4.19TIMECODE(IRIG)...................................... 36
10.4.20Synthesizer Frequency Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
10.5MenuTimeService .......................................... 37
10.5.1 Menu NTP Current State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
10.5.2 Menu: NTP Conguration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
10.5.3 Menu: Stratum of local clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
10.6 Programmable pulse (Option) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
10.6.1SETUPPOUTX ....................................... 39
10.6.2Mode ............................................. 40
10.6.3TimerMode.......................................... 40
10.6.4SinglePulse .......................................... 40
10.6.5Cyclicmode.......................................... 41
10.6.6PPS,PPM,PPHModes ................................... 41
10.7Menu:Network ............................................ 42
10.7.1 Menu: Global Conguration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
10.7.2 Menu: Setup Network Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
10.7.3 Menu: Setup IPv4 LAN Parameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
10.7.4 Menu: Setup IPv6 Parameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
10.7.5Menu:LinkMode....................................... 45
10.7.6Menu:NetworkServices ................................... 45
10.8Menu:System............................................. 46
10.8.1Menu:Settimezone ..................................... 46
10.8.2Menu:RestartNTP...................................... 47
11 The graphical user interfaces 48
12 The WEB Interface 49
12.1Conguration:MainMenu ...................................... 50
12.2Conguration:Ethernet........................................ 51
12.2.1SYSLOGServer........................................ 52
12.3 Network interface specic conguration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
12.3.1 IPv4 addresses and DHCP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
12.3.2 IPv6 addresses and autoconf . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
12.3.3 High Availability Bonding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
12.3.4 Additional Network Conguration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
12.4Conguration:Notication ...................................... 56
12.4.1AlarmEvents ......................................... 57
12.4.2E-mailmessages........................................ 58
12.4.3 Windows Popup Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
12.4.4SNMP-TRAPmessages.................................... 58
12.4.5 VP100/NET wall mount display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
12.4.6 User dened Alarm scripts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
12.4.7 NTPClientMonitoring .................................... 59
12.4.8Alarmmessages........................................ 59
12.5Conguration:Security ........................................ 60
12.5.1Password............................................ 61
12.5.2HTTPAccessControl..................................... 61
12.5.3SSHSecureShellLogin.................................... 61
12.5.4 Generate SSL Certicate for HTTPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
12.5.5 NTP keys and certicates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
12.5.6SNMPParameter ....................................... 64
12.6Conguration:NTP.......................................... 65
12.6.1NTPAuthentication...................................... 67
12.6.2NTPAUTOKEY ....................................... 68
12.7Conguration:Local.......................................... 71
12.7.1 Administrative functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
12.7.2UserManagement....................................... 72
12.7.3 Administrative Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
12.7.4SoftwareUpdate........................................ 75
12.7.5 Automatic conguration check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

12.7.6 Get Diagnostics Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
12.7.7ReceiverInformation ..................................... 77
12.7.8Webinterfacelanguage.................................... 77
12.8Conguration:Statistics........................................ 78
12.8.1 Statistical Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
12.9Conguration:Manual ........................................ 80
12.10Conguration:PTP.......................................... 81
12.10.1PTPv2 - Global Conguration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
12.10.2Option: PTP Client Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
12.10.3PTP Network Conguration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
12.10.4PTPStateFiles........................................ 86
13 The Command Line Interface 87
13.1CLIEthernet.............................................. 88
13.2CLINotication............................................ 90
13.3CLISecurity.............................................. 92
13.4CLINTPParameter.......................................... 94
13.4.1CLINTPAuthentication ................................... 95
13.5CLILocal ............................................... 95
14 SNMP Support 98
14.1CongurationoverSNMP....................................... 99
14.1.1 Examples for the usage of the SNMP conguration features . . . . . . . . . . . . . . . . 100
14.1.2 Further conguration possibilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
14.1.3 Send special timeserver commands with SNMP . . . . . . . . . . . . . . . . . . . . . . . 101
14.1.4 Conguration of the timeserver with SNMP: Reference . . . . . . . . . . . . . . . . . . . 103
14.2SNMPTraps..............................................108
14.2.1SNMPTrapReference ....................................108
15 Attachment: Technical Information 109
15.1 Skilled/Service-Personnel only: Replacing the Lithium Battery . . . . . . . . . . . . . . . . . . . 109
15.2 Technical Specications M600/300 Multipac . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
15.3 Safety instructions for building-in equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
15.3.1CE-Label............................................111
15.3.2 Compliance with International Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
15.4RearPanelConnectors ........................................113
15.5 Pin Assignment: Serial Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
15.5.1SerialTimeString.......................................114
15.5.2TERMINAL(Console).....................................114
15.6ErrorRelay...............................................115
15.6.1 Technical Specication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
15.7 Technical Specications GPS receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
15.7.1 Oscillator specications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
15.7.2 Technical Specications GPS Antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
15.8 Technical Specications LAN CPU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
15.9TimeCode...............................................120
15.9.1AbstractofTimeCode ....................................120
15.9.2 Block Diagram Time Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
15.9.3IRIGStandardFormat.....................................121
15.9.4AFNORStandardFormat...................................122
15.9.5 Assignment of CF Segment in IEEE1344 Code . . . . . . . . . . . . . . . . . . . . . . . . 123
15.9.6GeneratedTimeCodes ....................................124
15.9.7 Selection of Generated Time Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
15.9.8Outputs ............................................126
15.9.9TechnicalData ........................................126
15.10TimeStrings..............................................127
15.10.1Format of the Meinberg Standard Time String . . . . . . . . . . . . . . . . . . . . . . . . 127
15.10.2Format of the Meinberg GPS Time String . . . . . . . . . . . . . . . . . . . . . . . . . . 128
15.10.3Format of the Meinberg Capture String . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
15.10.4Format of the SAT Time String . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
15.10.5Format of the Uni Erlangen String (NTP) . . . . . . . . . . . . . . . . . . . . . . . . . . 131

Page 0
15.10.6Format of the NMEA 0183 String (RMC) . . . . . . . . . . . . . . . . . . . . . . . . . . 133
15.10.7Format of the NMEA 0183 String (GGA) . . . . . . . . . . . . . . . . . . . . . . . . . . 134
15.10.8Format of the NMEA 0183 String (ZDA) . . . . . . . . . . . . . . . . . . . . . . . . . . 135
15.10.9Format of the ABB SPA Time String . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
15.10.10Format of the Computime Time String . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
15.10.11Format of the RACAL standard Time String . . . . . . . . . . . . . . . . . . . . . . . . . 138
15.10.12Format of the SYSPLEX-1 Time String . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
15.10.13Format of the ION Time String . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
15.11Manual VP100/NET Display conguration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
15.12GlobalCongurationFile .......................................143
15.13GlobalOptionFile...........................................145
15.14Thirdpartysoftware..........................................146
15.14.1Operating System GNU/Linux . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
15.14.2Samba.............................................146
15.14.3Network Time Protocol Version 4 (NTP) . . . . . . . . . . . . . . . . . . . . . . . . . . 147
15.14.4mini_httpd ..........................................148
15.14.5GNU General Public License (GPL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
15.15ListofLiterature............................................153
16 Konformit¨ atserkl¨ arung 154
0 Date: 31st July 2014 LANTIME M600 MRS

Page 1
1 Impressum
Meinberg Funkuhren GmbH & Co. KG
Lange Wand 9, 31812 Bad Pyrmont - Germany
Phone: + 49 (0) 52 81 / 93 09 - 0
Fax: + 49 (0) 52 81 / 93 09 - 30
Internet: http://www.meinberg.de
Mail: [e-mail]
Date: 2010-04-07
LANTIME M600 MRS Date: 31st July 2014 1

Page 2 2 Quick Start
2 Quick Start
When booting the system the following message will be displayed while dots will be counted up in the lower line.
Approximately one minute after power up display will change to the following screen to wait for OCXO HQ
oscillator warmed up:
MEINBERG LANTIME
is booting... please wait...
.......
Main Menu will be displayed with some important status informations after booting has nished:
NTP: Offs. 1ms Stratum: 1
MRS: sync to GPS XTL:SYNC SVs:9/10
PTP: ok PTP_SLAVE GM:00:00:00:00:00:00
Press F1 for help or F2 for setup overview
F1
UTC
Tue, 01.01.2008
12:00:00
The internal reference clock (HQ OCXO) is either controlled by an installed GPS receiver or by external time
sources (depending on Options like IRIG in or PPS in). The priorities for this regulation can be dened in the
settings. Press the following buttons to set up the MRS mode: ↓, ok, ↓, ok, →, ok .
MRS Status
-> Setup Input Priorities <-
Setup Fixed Offsets
Setup Precisions
The priorities for the external reference sources will be setup in the next menu. The reference source with the
highest priority and has been synchronized will be the master to discipline the internal OCXO of the GPS/MRS
module:
1.GPS is master : -10ns
2.PPS in is available : -20ns
3.IRIG no signal : n/a
4.NTP is available : -30.000us
2.PTP (IEEE1588)is available : -300ns
F1
MRS Input Priorities
If the GPS receiver remains asynchronous the number of satellites in view and the good satellites are to check
2 Date: 31st July 2014 LANTIME M600 MRS

Page 3
(press buttons ↓,→,→,↓,→ from main menu). The antenna has to be installed without any obstructions to the
sky.
GPS Receiver Position
-> Satellite Constellation <-
GPS Status & Version
SATELLITE CONSTELLATION
satellites in view: 5
good satellites : 5
selected set: 04 09 21 17
For rst time installation enter TCP/IP address, netmask and default gateway. To get an overview of the current
conguration press F2 from main menu. Press F2 again to enter SETUP conguration page. Please ask your
administrator for proper TCP/IP conguration:
Global Configuration
->Network Interfaces <-
Network Services
Then press 3 times the OK button to change to IPV4 ETH0 conguration page to enter the IP address, netmask
and the default gateway:
ETH0: -> DHCP:disable <-
ADDRESS: 192.168.10.20
NETMASK: 255.255.255.000
DEF.GATEWAY: 192.168.10.1
NOTE: These settings are related to the rst 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
LANTIME M600 MRS Date: 31st July 2014 3

Page 4 3 Network Timeserver synchronized by multiple reference time sources
3 Network Timeserver synchronized by multiple
reference time sources
A 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 dier 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. Up to 7 NTP timeservers, external 1PPS or 10 MHz
signals, external IRIG Time Code signals or optionally a PTP IEEE 1588 grandmaster (M400, M600 and M900
only) can be used to control the internal oscillator.
The LANTIME/MRS is a set of equipment composed of a GPS170 satellite controlled clock, a single-board
computer with integrated network board, and a power supply, all installed in a metal 19 inch modular chassis
and ready to operate. Optionally a additional network card with hardware timestamping for the Precision Time
Protocol (PTP) IEEE 1588 will be integrated (M400, M600 and M900 only). A simplied LINUX operating
system is installed on the single-board computers ash disk. Eight push buttons and a display can be used to
congure and monitor the timeserver. After the network connection has been established the timeserver can
also be congured 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.
4 Date: 31st July 2014 LANTIME M600 MRS

Page 5
4 The Modular System LANTIME
LANTIME is a set of equipment composed of a satellite controlled clock GPS170, a single-board computer SBC
LX800 500 MHz with integrated network card, and a power supply unit, 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.
OK
ESC
Time Service
Ref. Time
Network
Alarm
Terminal
USB
F1
F2
12345
ENGLISH
1. VF Display 256 x 64 dots
2. Function buttons: 4-way navigation; F1, F2, OK, ESC
3. Status LEDs: Ref. Time, Time Service, Network, Alarm
4. Terminal / VT100, 38400 Baud, 8N1, 9pin. D-SUB male
5. USB connector
DEUTSCH
1. VF Display, 256 x 64 Punkte
2. Funktionstasten: 4 Wege Navigation; F1, F2; OK, ESC
3. Status LEDs: Ref. Time, Time Service, Network, Alarm
4. Terminal / VT100, 38400 Baud, 8N1, 9pol. D-SUB Stecker
5. USB Anschluss
LANTIME M600
NTP: Offs. PPS: 5us Stratum: 1
GPS: NORMAL OPERATION Satellites: 8/8
PTP2: ok INITIALIZING GM: 00...........
Press F1 for help or F2 for setup overview
07:23:25
UTC
Thu, 30.12.2010
GPS
Antenna
Error
O
I
100-240V AC
50/60Hz
1
43511
ENGLISH
1. Power supply connector
2. GPS Antenna, BNC
3. Serial Port COM 1, 9pin. D-SUB, female
4. Serial Port COM 0, 9pin. D-SUB, female
5. Error relay output, 3pin. DFK
6. PPS / Freq. In input, BNC
7. Time CodeAM / DCLS input, BNC
8. Time CodeAM / DCLS output, BNC
9. PPS / 10MHz output, BNC
10. F. Synth. / PPM output, BNC
11. Network connectors ETH0 - ETH3, 10/100 Mbit RJ45
DEUTSCH
1. Spannungsversorgung
2. GPS Antenne, BNC
3. Serielle Schnittstelle COM 1, 9pol. D-SUB Buchse
4. Serielle Schnittstelle COM 0, 9pol. D-SUB Buchse
5. Störmelderelaisausgang, 3pol. DFK
6. PPS / Freq. In Eingang, BNC
7. Time CodeAM / DCLS Eingang, BNC
8. Time CodeAM / DCLS Ausgang, BNC
9. PPS / 10MHz Ausgang, BNC
10. F. Synth. / PPM Ausgang, BNC
11. Netzwerk Anschlüsse ETH0 - ETH3, 10/100MBit RJ45
COM 1
COM 0
CO NO NC
100M 10M
ETH0
ETH1
2
PPS In
6
Freq. In
TC AM In
7
TC DCLS In
TC DCLS Out
8
TC AM Out
PPS Out
9
10MHz Out
F. Synth. Out
10
PPM Out
100M 10M
ETH2
ETH3
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 congured 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 conguration 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.
LANTIME M600 MRS Date: 31st July 2014 5

Page 6 4 The Modular System LANTIME
4.1 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 congurable
Autoconf Feature to be disabled
supported network services: NTP, HTTP, HTTPS, SNMP, SSH
- Windows net time via NETBIOS
- Winpopup (Window Mail)
4.2 Additional Features
• external NTP timeserver
• free conguration of NTP: thereby MD5 authentication and access control via address & mask restriction
• extended menu guidance for conguration and monitoring via Telnet, SSH or serial terminal interface
• 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 certicates, log les
and congurations, keypad locking
4.3 User Interface
• Terminal connection via serial interface, status LED
• Web browser interface with graphical statistic of the one-day cycle osets
• Telnet or Secure Shell Login for password protected operation of the Linux operating system
• FTP access for updating the operating system and downloading log les
• Simple Network Management Protocol for automatically SNMP-Traps in case of alarm
• SYSLOG messages can be passed to dierent computers
• Congurable e-mail notication
• Simulation of a synchronous radio clock in order to operate without antenna
6 Date: 31st July 2014 LANTIME M600 MRS

4.4 Input and Output Options Page 7
4.4 Input and Output Options
• Additional Ethernet RJ45 connectors available (eight in 3U housing, four in 1U housing and eight additional
connectors in HS - XL railmount housing)
• 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
• ANZ14NET or VP100/20/NET as display connected via network
4.5 Why to use a Network Time Server?
In principle it is possible to synchronize your computers with time servers on the internet. However, a lot of our
customers rely on their own time server in their network environment for security and/or maintainability reasons.
• Particularly in the case of our LANTIME you or a responsible person can be notied by mail or SNMP trap
if there is a malfunction in your time synchronization.
• The clients on the network do not depend on an active internet connection.
• The clients on the network do not depend on the availability of an external time server.
• A test of other freely available time servers reported that many NTP servers distributed a signicantly
wrong time, although they were classied as stratum-1 time servers. This is the responsibility of the server's
administrators.
• If an internet connection is working properly then NTP can determine and account for the packet transmis-
sion delays quite reliable. However, if the internet connection is at its capacity limit, time synchronization
can be signicantly degraded due to high dispersion in packet transmission delays. Reasons for this may be
hacker attacks, which must not address your own network, or new viruses causing a huge ood of emails,
like it has already happened in the past.
In the United States the U.S. Naval Observatory (USNO) has a similar function to spread the legal time as the
PTB in Germany, and also operates publicly available NTP servers for a long time. Those NTP servers are more
and more constrained by "bad" clients, which makes the future of the public service questionable. There are
already precautions to limit the aect of such clients. Dave Mills, the originator of NTP, cooperates with the
USNO and has already adverted this in the NTP news group.
The topics outlined above should provide some arguments to install an own time server, if an accurate time
is a requirement for the reliable operation of a local network.
LANTIME M600 MRS Date: 31st July 2014 7

Page 8 5 Network Time Protocol (NTP)
5 Network Time Protocol (NTP)
NTP is a common method for the synchronization of hardware clocks in local and global networks. The basic
concept, version 1 [Mills88], was published in 1988 as RFC (Request For Comments). Experiences acquired from
its practical use on the Internet was followed by version 2 [Mills89]. The NTP software package is an implemen-
tation of the actual version 3 [Mills90], based on the specication RFC-1305 from 1990 (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 operates in a way that is basically dierent from that of most other timing protocols. NTP does not
synchronize all connected clocks; instead it forms a hierarchy of timeservers and clients. Each level in this hier-
archy is called a stratum, and Stratum 1 is the highest level. Timeservers at this level synchronize themselves by
means of a reference time source such as a radio controlled clock, satelliet receiver or modem time distribution.
Stratum 1 Servers distribute their time to several clients in the network which are called Stratum 2.
Highly precise synchronization is feasible because of the several time references. Every computer synchronizes
itself with up to three valued time sources. NTP enables the comparison of the hardware times and the adjustment
of the internal clock. A time precision of 128 ms, and often better than 1 ms, is possible.
5.1 NTP Target
The NTP software package was tested on dierent UNIX systems. Many UNIX systems have an NTP client pre-
installed. Only some basic congurations need to be done (/etc/ntp.conf). NTP clients as freeware or shareware
are also available for most other operating systems like Windows 7/Vista/XP/NT/2000/98/95/3x, OS2 or MAC.
The following WEB site is recommended to get the latest version of NTP:
http://www.ntp.org
You can nd more information on our web page at: http://www.meinberg.de/english/sw/ntp.htm
5.2 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 le congures the compilation of the NTP daemon and all tools.
congure
All necessary information from the system will be collected and the corresponding make les 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 dierent ways. Either the system time can be set once by using the tool "ntp-
date lantime" or the NTPD daemon is started. In the rst case it is recommended to set the time automatically
with "cron" or once when booting the system. The second case is described below.
8 Date: 31st July 2014 LANTIME M600 MRS

5.2 NTP-Client Installation Page 9
First a le named /etc/ntp.conf has to be generated with an editor. Adapting the le to Meinberg LANTIME it
should contain the following:
# Example for /etc/ntp.conf for Meinberg LANTIME
server 127.127.1.0 # local clock
server 172.16.3.35 # TCPIP address of LANTIME
# optional: Driftle
# driftle /etc/ntp.drift
# optional: activate all messages in syslogle
# logcong =all
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 conguration).
e.g.: tail /var/log/messages
Shows the last lines from the le messages . The status messages can also be redirected in a log le by using the
following option:
ntpd -llogle
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:
         

         
         
with the following meaning:
- remote: list of all valid time servers (ntp.conf)
- red: 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)
- oset: dierence between system time and reference time
(milliseconds)
- jitter: variance of the osets (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 diers 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").
LANTIME M600 MRS Date: 31st July 2014 9

Page 10 6 GPS satellite controlled clock with MRS option
6 GPS satellite controlled clock with MRS option
Lantime/MRS is a Multi Reference Source time server. The reference time base, integrated into the LANTIME,
consists of a high precision oscillator OCXO HQ. This oscillator can be optionally controlled by the integrated
GPS receiver, an external Puls Per Second (PPS input), Standard Frequency Input (10MHz), an IRIG time code
receiver, by max. 7 external NTP servers or by a PTP IEEE 1588 Time Stamp Unit (M400, M600 and M900
only). In any case a OCXO oscillator is used as a reference for internal NTP, even if GPS reception or external
reference clock are not available. All outputs like serial output, PPS output or 10MHz will be driven by the
internal oscillator. The priority which reference clock will discipline the internal OCXO can be set up in a user
dened list via the display or the HTTP interface.
6.1 MRS functionality
After power up the system the internal clock module will be free running on an internal oscillator. If the GPS
receiver or one of the external reference sources are available and synchronized then the internal clock will be set
once and the internal OCXO will be adjusted. For the rst time adjust with an external NTP server the system
will wait until the internal NTP has been synchronized and the time oset is below 1 ms (this will take appr. 5
Min). After that the oset to the external NTP server will be calculated and set the internal clock module. The
following reference clocks are possible (depending on the expansions):
• GPS / GLONASS receiver
• IRIG time code receiver with DCLS or modulated
• Pulse Per Second Input (PPS in)
• up to 7 external NTP server
• PTP IEEE-1588 (M400, M600 and M900 only)
• Pulse Per Second plus serial time string (STR)
• Freq. In.
If more than one reference clock is available and synchronized then the clock with the highest priority will be taken
to adjust the internal OCXO. This reference clock will be called master clock. If this master clock is unavailable a
dierent clock with the highest priority will be chosen. If a reference clock with a higher priority than the current
master will be available the master clock will be switched to the higher priority.
Each external reference source can be set with a bias (a x oset), if you know the constant oset (bias) of
an external reference source. By default this value is 0 ns. The bias of the internal GPS receiver can not be set
up - indirectly this can be done via the antenna cable length.
Each reference clock can be assigned a specic precision which will reect the accuracy of the reference clock.
This precision value will determine the hold over time when switching to the next reference clock if the current
master is not available anymore. If the precision is set to 0 then the next reference clock will be switched at
once. If the precision value is greater then 0 the time for switching to the next reference (hold over time) will be
calculated by the following formula:
(precision of next reference) / (precision of current master) * constant [s]
The parameter "constant" depends on the quality of the internal oscillator.
Example: the external PPS with an precision of 100ns is the current master. If this master is no longer available
it will switch to the next reference source of the priority order - in this case the IRIG input with an precision of
10us. With the formula ((10000ns/100ns)*11.4) we get hold over time of 19min. The online display of the MRS
status will show the remaining time and the calculated time. The hold over time will be recalculated if the status
of the reference clocks will change.
10 Date: 31st July 2014 LANTIME M600 MRS

6.1 MRS functionality Page 11
The internal NTP is not requesting the external reference clocks directly. It will see only the internal clock
of the GPS/MRS module with its high precision oscillator OCXO. The controlling of the internal OCXO will be
done by the GPS/MRS module. All osets from the internal reference time to the external reference clocks will
be send to the GPS/MRS clock. The external NTP server will be congured as "server" at the internal NTP
with the option "noselect" only to get the osets to the external NTP servers.
The status information of the activated reference clocks will be shown in the display. The state of the mas-
ter will be marked with "*" or written as text. Also the oset from the reference clock to the internal clock will
be displayed.
1.GPS * 20ns 2.PPS 30ns
2.NTP 30.000us
1.GPS is master : -10ns
2.PPS in is available : -20ns
3.IRIG no signal : n/a
4.NTP is available : -30.000us
2.PTP(IEEE1588)is available : -300ns
F1
MRS Input Priorities
1.GPS * 20ns
2.PPS 30ns
3.NTP 30.000us
M300: LC-Display 40 x 2 Characters
M400 / M900: LC-display, 4 x 16 Characters
M600: Vacuum fluorescent graphic display (VFD), 256 x 64 dots
If an external PTP IEEE1588 grandmaster is available the reference source will be taken prior to the external
NTP server. The PTP time stamping unit will be scanned every 10 seconds (independently of the broadcast
interval of the PTP master). The external NTP server will be scanned every 64 seconds.
After setting the time oset of the internal clock module the NTP will be restarted. Now only small oset
values will be sent to the internal clock module; the ne synchronization mode will start. In the "ne synchro-
nization mode" all osets greater than 10 ms will be ignored 5 times in a row - after the 5 times the oset will be set.
IMPORTANT: After power up the Lantime/MRS the maximum time dierence between internal clock and
external NTP server or PTP grandmaster must be lower than 1000s. Otherwise the internal clock must be set
manually via LC-Display or synchronized by GPS once.
LANTIME M600 MRS Date: 31st July 2014 11

Page 12 6 GPS satellite controlled clock with MRS option
6.2 GPS functionality
A Meinberg GPS170 satellite controlled radio clock is used as a reference time base. The satellite receiver clock
GPS170 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 sys-
tem. 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 oset 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 oset 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 oset, 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.
6.3 GPS Clock Features
The GPS clock module is a 100 mm x 160 mm microprocessor board, and is connected to the antenna/converter
unit by a 50 ohm coaxial cable (refer to "Mounting the Antenna"). DC power to fed to the antenna/downcon-
verter via the antenna cable. An optional antenna splitter is available to operate up to four receivers from a single
antenna.
The navigation message coming in from the satellites is decoded by the GPS clcok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 for the oscillators aging. The last recent value is restored from
the battery buered memory at power-up.
6.4 Time Zone and Daylight Saving
GPS system time diers from the universal time scale (UTC) by the number of leap seconds which have been
inserted into the UTC time scale since GPS was initiated in 1980. The current number of leap seconds is part of
the navigation message supplied by the satellites, so the internal real time of the GPS170 is based on UTC time
scale. Conversion to local time and annual daylight saving time can be done by the receiver's microprocessor if
the corresponding parameters are set up by the user.
12 Date: 31st July 2014 LANTIME M600 MRS

Page 13
7 Mounting the GPS Antenna
The GPS satellites are not stationary, but circle round the globe with 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/downconverter
unit must be installed in a location that has as clear a view of the sky as possible. The best reception is achieved
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 the clearest free view to the equator, because the satellite orbits are located between
latitudes 55
◦
North and 55
◦
South. If this is not possible, you may experience diculty receiving the four satellites
necessary to complete the receiver's position solution.
The antenna/converter unit can be mounted on a wall, or on a pole up to 60 mm in diameter. A 45 cm
plastic tube, two wall-mount brackets, and clamps for pole mounting are included with every GPS170. A standard
RG58 coaxial cable should be used to connect the antenna/downconverter unit to the receiver. The maximum
length of cable between antenna and receiver depends on the attenuation factor of the coaxial cable.
Up to four GPS170 receivers can be run with one antenna/downconverter unit by using an optional antenna
splitter. The total length of an antenna line from antenna to receiver must not be longer than the max. length
shown in the table below. The position of the splitter in the antenna line does not matter.
High voltage protectors must be installed directly after reaching the indoors. The optional delivered protec-
tion kit is not for outdoor usage.
7.1 Example:
Type of cable diameter Ø Attenuation at 100MHz max lenght.
[mm] [dB]/100m [m]
RG58/CU 5mm 17 300 (1)
RG213 10.5mm 7 700 (1)
(1)This specications are made for antenna/converter units produced after January, 2005
The values are typically ones; the exact ones are to nd out from the data sheet of the used cable
LANTIME M600 MRS Date: 31st July 2014 13

Page 14 7 Mounting the GPS Antenna
7.2 Antenna Assembly with Surge Voltage Protection
Optional a surge voltage protector for coaxial lines is available. The shield has to be connected to earth as short
as possible by using the included mounting bracket. Normally you connect the antenna converter directly with
the antenna cable to the system.
14 Date: 31st July 2014 LANTIME M600 MRS