Meinberg LANTIME M300 User manual

MANUAL
LANTIME M300 PZF
DCF77 NTP Server
7th November 2011
Meinberg Radio Clocks GmbH & Co. KG

Table of Contents
1 Impressum 1
2 Quick Start 2
3 Network Timeserver with DCF77 synchronized time base 3
4 The Modular System LANTIME 4
4.1 SupportedNetworkServices...................................... 5
4.2 AdditionalFeatures .......................................... 5
4.3 UserInterface ............................................. 5
4.4 Options ................................................ 6
4.5 Why to use a Network Time Server? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5 Network Time Protocol (NTP) 7
5.1 NTPTarget .............................................. 7
5.2 NTP-ClientInstallation ........................................ 7
6 General information PZF 9
6.1 FeaturesofPZF600.......................................... 9
7 DCF77 Antenna 11
7.1 AssemblyoftheAntenna ....................................... 11
8 Booting the PZF receiver 12
9 Booting the Single Board Computer 13
10 Configuration User Interface 14
10.1 Introduction: Conguration LANTIME . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
10.2RootMenu............................................... 14
10.3Menü:ReferenceTime ........................................ 17
10.3.1InfoPZF............................................ 17
10.3.2PZFStatusandVersion.................................... 17
10.3.3CorrelationandField ..................................... 18
10.3.4SetupPZF........................................... 18
10.3.5TransmitterDistance ..................................... 18
10.3.6 Ignore Lock (Simulation Mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
10.3.7InitialTime .......................................... 19
10.3.8SerialOutputs......................................... 19
10.4Menu:TimeService.......................................... 20
10.4.1Menu:externalNTP ..................................... 20
10.4.2 Menu: Stratum of local clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
10.4.3Menu:RestartNTP...................................... 20
10.5Menu:Network ............................................ 21
10.5.1 Setup Global Conguration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
10.5.2 Setup Network Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
10.5.3 Setup Network Ipv4 Parameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
10.5.4 Menu: Setup Ipv6 Parameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
10.5.5Menu:LinkMode....................................... 23
10.5.6 Menu: Setup Network Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
10.6Menu:System............................................. 23
10.6.1Settimezone ......................................... 24
11 The WEB Interface 26
11.1Conguration:MainMenu ...................................... 26
0

11.2Conguration:Ethernet........................................ 28
11.2.1SYSLOGServer........................................ 29
11.3 Network interface specic conguration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
11.3.1 IPv4 addresses and DHCP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
11.3.2 IPv6 addresses and autoconf . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
11.3.3 High Availability Bonding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
11.3.4 Additional Network Conguration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
11.4Conguration:Notication ...................................... 32
11.4.1Alarmevents.......................................... 32
11.4.2E-mailmessages........................................ 33
11.4.3 Windows Popup Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
11.4.4SNMP-TRAPmessages.................................... 34
11.4.5 VP100/NET wall mount display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
11.4.6 User dened Alarm scripts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
11.4.7 NTPClientMonitoring .................................... 34
11.4.8Alarmmessages........................................ 35
11.5Conguration:Security ........................................ 36
11.5.1Password............................................ 37
11.5.2HTTPAccessControl..................................... 37
11.5.3SSHSecureShellLogin.................................... 37
11.5.4 Generate SSL Certicate for HTTPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
11.5.5 NTP keys and certicates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
11.5.6SNMPParameter ....................................... 39
11.6Conguration:NTP.......................................... 40
11.6.1NTPAuthentication...................................... 42
11.6.2NTPAUTOKEY ....................................... 43
11.7Conguration:Local.......................................... 46
11.7.1 Administrative functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
11.7.2UserManagement....................................... 47
11.7.3 Administrative Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
11.7.4SoftwareUpdate........................................ 49
11.7.5 Automatic conguration check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
11.7.6 Get Diagnostics Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
11.7.7ReceiverInformation ..................................... 51
11.7.8Webinterfacelanguage.................................... 51
11.8Conguration:Statistics........................................ 52
11.8.1 Statistical Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
11.9Conguration:Manual ........................................ 54
11.10Conguration:PTP.......................................... 55
11.10.1PTPv2 - Global Conguration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
11.10.2PTP Network Conguration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
11.10.3PTPStateFiles........................................ 59
12 The Command Line Interface 60
12.1CLIEthernet.............................................. 61
12.2CLINotication............................................ 63
12.3CLISecurity.............................................. 65
12.4CLINTPParameter.......................................... 67
12.4.1CLINTPAuthentication ................................... 68
12.5CLILocal ............................................... 68
13 SNMP Support 71
13.1CongurationoverSNMP....................................... 72
13.1.1 Examples for the usage of the SNMP conguration features . . . . . . . . . . . . . . . . 72
13.1.2 Further conguration possibilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
13.1.3 Send special timeserver commands with SNMP . . . . . . . . . . . . . . . . . . . . . . . 73
13.1.4 Conguration of the timeserver with SNMP: Reference . . . . . . . . . . . . . . . . . . . 75
13.2SNMPTraps.............................................. 79
13.2.1SNMPTrapReference .................................... 80

Page 0
14 Attachment: Technical Information 81
14.1 Skilled/Service-Personnel only: Replacing the Lithium Battery . . . . . . . . . . . . . . . . . . . 81
14.2 Technical Specications M600/300 Multipac . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
14.3 Safety instructions for building-in equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
14.3.1CE-Label............................................ 82
14.4RearPanelConnectors ........................................ 83
14.5 Pin Assignment: Serial Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
14.5.1SerialTimeString....................................... 83
14.6ErrorRelay............................................... 83
14.6.1 Technical Specication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
14.7 Technical specications PZF600 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
14.8 Technical Specications LAN CPU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
14.8.1 Rear Connector Pin Assignments LAN CPU . . . . . . . . . . . . . . . . . . . . . . . . . 87
14.8.2 VGA, Keyboard Connector Pin Assignments . . . . . . . . . . . . . . . . . . . . . . . . . 87
14.9 Manual VP100/NET Display conguration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
14.10GlobalCongurationFile ....................................... 89
14.11GlobalOptionFile........................................... 91
14.12Thirdpartysoftware.......................................... 91
14.12.1Operating System GNU/Linux . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
14.12.2Samba............................................. 91
14.12.3Network Time Protocol Version 4 (NTP) . . . . . . . . . . . . . . . . . . . . . . . . . . 91
14.12.4mini_httpd .......................................... 92
14.12.5GNU General Public License (GPL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
14.13USBStick ............................................... 97
14.13.1Menu Backup Conguration to USB Stick . . . . . . . . . . . . . . . . . . . . . . . . . . 97
14.13.2Menu Write Diagnostic File to USB Stick . . . . . . . . . . . . . . . . . . . . . . . . . . 97
14.13.3Keypadlocking ........................................ 97
14.13.4Menu Restore Conguration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
14.14Reference ............................................... 98
0 Date: 7th November 2011 LANTIME M300 PZF

Page 1
1 Impressum
Meinberg Radio Clocks 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: 2010-11-15
LANTIME M300 PZF Date: 7th November 2011 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:.
MEINBERG TIMESERVER please wait...
.......
Main Menu will be displayed with some important status informations after booting has nished:
PZF: NORMAL OPERATION Fri, 11.05.2009
NTP: not sync UTC 09:12:11
PZF: NORMAL OPERATION Fri, 11.05.2009
NTP: not sync UTC 09:12:11
If the DCF77 PZF receiver remains asynchronous (Ref.Time LED is still red after 3 minutes) the Field and the
Correlation (at least 60, optimum 99) are to check (press buttons i,ok from main menu). The antenna has to
be installed with the longer side to direction of Frankfurt in Germany.
PZF STATE: CORR.: 90 State:fine
FIELD: 94
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 Cfg. Services
Interfaces-> <-
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:
SETUP: Ipv4 LAN Parameter ETH0
Ipv4 ADDRESS: 192.168.10.200
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
2 Date: 7th November 2011 LANTIME M300 PZF

Page 3
3 Network Timeserver with DCF77 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 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. LANTIME M300 / PZF (equivalent to LANTIME/PZF)
is a set of equipment composed of a DCF77 controlled clock, 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 simplied
LINUX operating system is installed on the single-board computers ash disk. Eight push buttons and a 2 x 40
character LC display can be used to congure and monitor the time server. After the network connection has
been established the time server 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.
LANTIME M300 PZF Date: 7th November 2011 3

Page 4 4 The Modular System LANTIME
4 The Modular System LANTIME
LANTIME time server is a set of equipment composed of a reference clock (e.g.: satellite controlled clock GPS,
correlation receiver PZF or time code reader TCR), 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
5
9
1
6
PZF: NORMAL OPERATION
NTP: Offset PPS: -4µs UTC 12: 00 : 00
Mon , dd.mm.yyyy
LANTIME M300LANTIME M300
F1
F2
LC - Display backlight
2 x 40 chars
Mounting wholes
for 19” cabinet
USB connector for USB Stick
Terminal connector
serial interface
Vt100, 38400Baud,8N1
Nullmodem to PC
ESC button: cancel menu and one level up
OK button: save changes or enter submenu
4 arrow buttons: select next menu and change value of parameters
F1 button: show help and additional informations
F2 button: overview of network parameters
Status LED Referenz time: green: synchronized red: error
Status LED NTP time service: green: synchronized red: error
Status LED Network connection: green: Link red: error
Status LED Alarm: red: error
COM 0
TxD0
Error
PZF
Antenna CO NO NC
1
6
5
9
1
6
5
9
100M 10M 100M 10M
ETH0 ETH2
ETH1 ETH3
PPS Out
10MHz Out
O
I
100-240V AC
50/60Hz
2 Network connectors ETH0, ETH1
10/100 Mbit Rj45
LNE Optional
Standard Pulse per second
output 10MHz output (TTL) Rs232 output serial interface timecode
Time Sync Error Relais
Output
Power supply input see
technical specification
PZF antenna BNC
The implemented NTPD distributes the reference time from the 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.
4 Date: 7th November 2011 LANTIME M300 PZF

4.1 Supported Network Services Page 5
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
LANTIME M300 PZF Date: 7th November 2011 5

Page 6 4 The Modular System LANTIME
4.4 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.
6 Date: 7th November 2011 LANTIME M300 PZF

Page 7
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.eecis.udel.edu/ ntp/
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.
LANTIME M300 PZF Date: 7th November 2011 7

Page 8 5 Network Time Protocol (NTP)
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").
8 Date: 7th November 2011 LANTIME M300 PZF

Page 9
6 General information PZF
The German long wave transmitter DCF77 started continuous operation in 1970. The introduction of time codes
in 1973 build the basic for developing modern radio remote clocks.
The carrier frequency of 77.5 kHz is amplitude modulated with time marks each second. The BCD-coding
of the time telegram is done by shifting the amplitude to 25% for a period of 0.1s for a logical '0' and for 0.2s
for a logical '1'. The receiver reconstructs the time frame by demodulating this DCF-signal. Because the AM-
signal is normally superimposed by interfering signals, ltering of the received signal is required. The resulting
bandwidth-limiting causes a skew of the demodulated time marks which is in the range of 10 ms. Variations of
the trigger level of the demodulator make the accuracy of the time marks worse by additional +/-3 ms. Because
this precision is not sucient for lots of applications, the PTB (Physical and Technical Institute of Germany)
began to spread time information by using the correlation technique.
The DCF-transmitter is modulated with a pseudo-random phase noise in addition to the AM. The pseudo-random
sequence (PZF) contains 512 bits which are transmitted by phase modulation between the AM-time marks. The
bit sequence is build of the same number of logical '0' and logical '1' to get a symmetrical PZF to keep the
average phase of the carrier constant. The length of one bit is 120 DCF-clocks, corresponding to 1,55 ms. The
carrier of 77.5 kHz is modulated with a phase deviation of +/-10
◦
per bit. The bit sequence is transmitted each
second, it starts 200ms after the beginning of an AM second mark and ends shortly before the next one.
Compared to an AM DCF77-receiver, the input lter of a correlation receiver can be dimensioned wide-bandwidth.
The incoming signal is correlated with a reconstructed receiver-PZF. This correlation analysis allows the generation
of time marks which have a skew of only some microseconds. In addition, the interference immunity is increased
by this method because interference signals are suppressed by averaging the incoming signal. By sending the
original or the complemented bit sequence, the BCD-coded time information is transmitted.
The absolute accuracy of the generated time frame depends on the quality of the receiver and the distance
to the transmitter, but also on the conditions of transmission. Therefore the absolute precision of the time frame
is better in summer and at day than in winter and at night. The reason for this phenomenon is a dierence in
the portion of the sky wave which superimposes the ground wave. To check the accuracy of the time frame, the
comparison of two systems with compensated propagation delay is meaningful.
6.1 Features of PZF600
The PZF600 is a high precision receive module for the DCF77-signal build in euro card size (100 mm x 160 mm).
The micro controller of the system correlates its receiver-PZF with the incoming pseudorandom sequence and
decodes the time information of the DCF-telegram simultaneously. The controller handles input and output func-
tions of the PZF600 and synchronizes the internal real-time clock.
By evaluating the pseudorandom phase noise, the PZF600 is able to generate time frames with thousand times
the accuracy of standard AM-time code receivers. The precise regulation of the main oscillator (TCXO, OCXO
optional for higher accuracy) of the radio clock is possible therefore. So, the PZF600 can be used as a standard
frequency generator besides the application as a time code receiver. Six xed and one settable TTL-level standard
frequencies are available at the rear VG-connector. The synthesizer frequency exists as an open drain output and
a sine wave signal also.
The PZF600 delivers TTL-low and TTL-high active pulses per minute and per second further. To distribute
information concerning date, time and status, two independent serial interfaces (RS232) are used which are con-
gurable in a setup menu.
Like mentioned before, the PZF600 includes a battery-backed real-time clock which runs crystal-precise if the
main power supply fails.
LANTIME M300 PZF Date: 7th November 2011 9

Page 10 6 General information PZF
Important system parameters are stored in a battery-backed (RAM of the RTC) or non-volatile (EEPROM)
memory.
If an update of system software becomes necessary, the new rmware can be loaded via serial interface (COM0)
without removing the PZF600 for inserting a new EPROM.
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Page 11
7 DCF77 Antenna
The PZF Radio Clock operates with a ferrite antenna which is damped to match the bandwidth needed for the
correlation reception. The IP-Code is: IP56
7.1 Assembly of the Antenna
The antenna has to be mounted as exactly as possible. Turning it out of the main receive direction will result in
less accurate time frames. The antenna must be placed in longitudinal direction to the DCF-transmitter (Frank-
furt). The nearness to microcomputers should be avoided and the antenna should be installed with a minimum
distance of 30 cm to all metal objects, if possible. A distance of several meters to TV- or computer monitors
must be kept.
After switching the PZF to the menu 'PZF STATE', the adjustment of the antenna can be executed. The
displayed value is proportional to the received eld strength. The best method of mounting the antenna is to look
for the minimum eld strength and turn the antenna by 90
◦
to maximum then. A high eld strength on its own
is no guarantee for good conditions of reception, because interfering signals within the bandwidth of the receiver
also have an eect on the displayed value.
The maximum interference immunity can be found by looking at the autocorrelation coecient (in percent)
in the menu 'PZF-STAT'. The displayed value should be close to 99 % for best reception.
LANTIME M300 PZF Date: 7th November 2011 11

Page 12 8 Booting the PZF receiver
8 Booting the PZF receiver
If both, the antenna and the power supply, have been connected the system is ready to operate. About 10 sec-
onds after power-up the receivers TCXO has warmed up and operates with the required accuracy. Press bottons
i,gfrom main menu to check the eld and correlation values. The correlation "State" starts in "row" mode. If
a good correlation has been found the receiver check 20 times this new correlation: this State is called "check"
and the correlation value counts from 1 to 20. If the correlation is stell good the State changes to "ne" mode.
PZF STATE: CORR.: 18 State:row
FIELD: 0
PZF STATE: CORR.: 1 State:check
FIELD: 94
PZF STATE: CORR.: 90 State:fine
FIELD: 94
12 Date: 7th November 2011 LANTIME M300 PZF

Page 13
9 Booting the Single Board Computer
The LINUX operating system is loaded from a packed le on the ash disk of the single board computer to a
RAM disk. All les of the ash disk are stored in the RAM disk after booting. Because of that it is guaranteed
that the le system is in a dened condition after restart. This boot process takes approx. two minutes. During
this time the following message appears on the display:
MEINBERG TIMESERVER please wait...
.......
After starting up the LINUX system the network function is initiated and the program for communication with
the PZF600 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 DCF77 PZF receiver). Until synchronisa-
tion is nished the following message is displayed:
PZF: NORMAL OPERATION Fri, 15.12.2005
NTP: not sync UTC 09:12:11
For the synchronisation of the NTPD with the PZF it is necessary that the DCF77 PZF receiver is synchronous
with the DCF77 time ("Ref.Time" LED is green). In this case the following message is monitored on the display.
PZF: NORMAL OPERATION Fri, 15.12.2005
NTP: Offset PPS: 1ms UTC 09:14:16
The second line shows the user that the NTPD is synchronized with the PZF with an oset of -1 ms. Because
of the internal time of the NTP which is adjusted by a software PLL (phase locked loop) it takes a certain time
to optimise this oset. The NTPD tries to keep the oset below +-128 ms; if the oset becomes too large the
system time is set with the DCF77-time. Typically values for the oset are +-5 ms after the NTPD has already
synchronized.
LANTIME M300 PZF Date: 7th November 2011 13

Page 14 10 Conguration User Interface
10 Configuration User Interface
10.1 Introduction: Configuration LANTIME
There are several ways to congure the LANTIME parameters:
Command Line Interface (CLI) via TELNET
Command Line Interface via SSH
Command Line Interface via serial terminal in front panel
(38400/8N1/VT100)
HTTP Interface
Secure HTTP Interface (HTTPS)
Front panel LCD/VFD Interface
SNMP Management
In order to be able to congure the time server via the web interface or a telnet/SSH connection, an IP address
has to be assigned via the front panel keys and LC/VF display (for automatic assignment possibilities please refer
to: DHCP IPv4 or AUTOCONF IPv6). LANTIME variants without a display can be congured using the serial
terminal interface (labeled Term or Terminal) The termin program should be set to 38400Baud / 8N1  VT100
emulation. Once the IPv4 address, net mask and IPv4 GATEWAY have been set up or the network interface has
been automatically congured with DHCP/Autoconf, further conguration changes can be done via a network
connection:
To set up a TELNET connection the following commands are entered:
telnet 198.168.10.10 // LANTIME IP address
user: root
password: timeserver
With setup the conguration program is started.
To set up a SSH connection the following commands are entered:
ssh ro[email protected] // LANTIME IP address
password: timeserver
With setup the conguration program is started.
To set up a HTTP connection the following address is to enter in a web browser:
http://198.168.10.10 // LANTIME IP address
password: timeserver
To set up a Secure HTTP (HTTPS) connection the following address is entered in a web browser:
https://198.168.10.10 // LANTIME IP address
password: timeserver
10.2 Root Menu
The root menu is shown when the receiver has completed initialization after power-up. With the four arrow
buttons and the buttons OK, ESC, F1 and F2 the navigation and setting of parameters can be managed.
Main menu can be reached by pressing ESC some times. The main menu reect some of the main parameters
of the time server.
First line displays the status of the reference clock. After the start-up, the Lantime is not synchronized and
the text "NOT SYNC" is displayed. If the text "NORMAL OPERATION" appears, the system is already syn-
chronized. If the antenna is disconnected or not working properly, the text "NOT AVAILABLE" is displayed instead.
14 Date: 7th November 2011 LANTIME M300 PZF

10.2 Root Menu Page 15
PZF: NORMAL OPERATION Mon, 28.08.2006
NTP: not sync UTC 14:33:10
OK
ESC
F1
F2
Current time and date of the timeserver with the name
of the time zone (NTP uses UTC time zone) will be
monitored on the right side. The multicolor LEDs will
reect the current state of the device:
Time Service
Ref. Time
Network
Alarm
Ref. Time
green: the reference clock (e.g. integrated PZF600) produce valid time.
red: the reference clock produce no valid time (e.g. not synchronized)
Time Service
green: NTP has been synchronized to reference clock.
red: NTP is not synchronous to reference clock or sync to local clock
Network
green: all watched network ports has been link up detected
red: at least one of the watched network ports (look at Setup Device
Parameter / Check Network Linkup) is not connected
Alarm
o: no error at moment
ret: general error  more information will be shown on display.
When pressing the OK button from main menu the version of the LANTIME software, the NTP and the LINUX
kernel version will be displayed.
TYP:ELX800 PZFXXX M3x VX.xx 2.6.12
SN:030100000000 NTP: 4.2.0
The following main menus will be displayed when pressing the UP and DOWN arrow buttons:
LANTIME M300 PZF Date: 7th November 2011 15