Mobatime WTD 868-T-V2 User manual

© MOBATIME BE-800905.01
INSTRUCTION MANUAL
Wireless Time Distribution WTD 868-T-V2

© MOBATIME 2 / 20 800905.01
Manufacturer’s Certificate
STANDARDS
The WTD 868-T-V2 time signal transmitter was developed and produced in accordance with the EU
guideline 1999 / 5 / EWG
Notes to the Instruction Manual
1. The information contained in this instruction manual can be changed at any time without prior notice.
The current version is available for downloading under www.mobatime.com.
2. This instruction manual was compiled with the utmost care to provide all the details regarding the use
of this product. However, should you have any queries, or find any errors in the instructions, please
contact us.
3. We will not accept any liability for any damages resulting, directly or indirectly, from the use of this
instruction manual.
4. Please read these instructions carefully and only use the product when all the instructions on installing
and operating have been correctly understood.
5. Installation may only be carried out by qualified personnel.
6. This publication, or any extracts from it, may not be reproduced, stored in a electronic retrieval system,
or in any way transmitted. The copyright with all its rights lies with BÜRK MOBATIME GmbH,
D-78026 VS-Schwenningen and MOSER-BAER AG, CH–3454 Sumiswald / Switzerland.

© MOBATIME 3 / 20 800905.01
Contents
1 Introduction..................................................................................................................................................4
2 Hardware Description .................................................................................................................................5
2.1 Connections ........................................................................................................................................5
2.1.1 LAN Ethernet 10Mbit/s ....................................................................................................................................................5
2.1.2 Time signal input DCF In .................................................................................................................................................5
2.1.3 Power supply input DC In ................................................................................................................................................6
2.1.4 Status LED......................................................................................................................................................................6
3 Synchronisation ..........................................................................................................................................7
3.1 DCF Time Signal.................................................................................................................................7
3.2 NTP Server..........................................................................................................................................7
3.3 Time Acceptance.................................................................................................................................7
3.4 Loss of Synchronisation ......................................................................................................................7
3.5 Accuracy..............................................................................................................................................7
3.6 Time Zone Entry..................................................................................................................................7
3.6.1 Standard time zone table.................................................................................................................................................7
3.6.2 Time Zone Server............................................................................................................................................................8
4 Configuration ...............................................................................................................................................9
4.1 Configuration switch............................................................................................................................9
4.1.1 Synch. / RF settings switch..............................................................................................................................................9
4.1.2 LAN / Time Settings Switch ...........................................................................................................................................11
5 Installation..................................................................................................................................................12
5.1 Instructions ........................................................................................................................................12
6 Internet Group Management Protocol (IGMP) ........................................................................................13
6.1 Use ....................................................................................................................................................13
7 Standard Time Zone Table........................................................................................................................14
8 Technical Details .......................................................................................................................................16

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1 Introduction
The WTD 868-T-V2 is an HF transmitter for the wireless synchronisation of analogue and
digital radio-controlled slave clocks.
(WTD = Wireless Time Distribution, 868 = Frequency band 868 MHz, T = Transmitter).
The transmitter can be synchronised (NTP), and supplied (Power over Ethernet PoE) from a
local network (LAN). The transmitter can, however, also be supplied from an external direct
current supply, and synchronised with a time signal receiver (DCF/HBG/MSF/GPS). Should
the WTD 868-T-V2 serve as a radio interface for a master clock (ETC, CTC, MTC), it can be
synchronised from its DCF output.
The transmitter is completely compatible with the NF S87-500 standard of the French
Standards Association (AFNOR). The standard includes a description of the time code format
for wireless time distribution.

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2 Hardware Description
2.1 Connections
2.1.1 LAN Ethernet 10Mbit/s
yellow green
RJ 45 plug for 10BaseT cable
Integrated LEDs:
Yellow: Connection (shows connection to LAN)
Green: Activity (signalises sending / receipt of data packets)
The RJ 45 plug is PoE capable (Power over Ethernet). The WTD 868-T-V2 can thus be
supplied directly from the LAN. Either with phantom power or via the connections 4,5
and 7,8 (protected against polarity reversal).
2.1.2 Time signal input DCF In
-+
Active current loop input for DCF time code from the time signal receiver DCF 450(0) /
MSF 450(0), HBG 450(0) / GPS 4500 (receiver type adjustable) or from the master
clock (e.g. ETC, CTC, MTS, MTC).

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2.1.3 Power supply input DC In
This connection (DC in: - / +) can be used to supply the WTD 868-T-V2 from an
external direct power supply, if no PoE (Power over Ethernet) is available.
If an external switching power supply unit is used, it must fulfill the following
specifications:
- 24 VDC, max. 15VA
- Certified with EN/IEC 60950-1 (e. g. CE, GS, UL)
An earth connection enables the signal ground (-) of the WTD 868-T-V2 to be
connected electrically to the earthing potential. This connection can be especially
useful in the case of difficult DCF reception to clear the fault (Follow the specifications
for the receiver). Take a power supply 24V= / 48V= max. 300mA.
Electrical characteristics DC in: 15..56 V=, current consumption <100 mA @48 V=,
respectively <300 mA @15 V=.
When synchronising with a DCF, HBG or MSF time signal receiver, the input voltage
should not be lower than 20 V= (Follow the specifications for the receiver).
When synchronising with a GPS 4500 time signal receiver, the common supply voltage
of 40 V= may not be exceeded and the current consumption of the receiver should be
observed when selecting the power supply (Follow the specifications for the receiver).
2.1.4 Status LED
If there is power on the WTD 868-T-V2, the LED (status: wait for synchronisation) will
appear. As soon as the interface is synchronised, the status LED will go out. During
transmission activity, the LED lights up briefly (the periodicity of the flashing depends
on the transmitter address set). After 1 hour without synchronisation, the LED will light
permanently.
Operating modes / Status LED displays
LED Cause / Remedy
Lights permanently -Power on after startup
-or after 1 hour without synchronisation
Status: wait for synchronisation
Doesn't light up Normal operation when synchronisation is OK.
Brief, periodical light up During transmission activity, the LED lights up briefly (the
periodicity of the flashing depends on the transmitter
address set).

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3 Synchronisation
3.1 DCF Time Signal
The WTD 868-T-V2 can function as a DCF synchronised radio-controlled master clock.
In addition, the transmitter can be synchronised directly from a time signal receiver
(DCF 450(0) / MSF 450(0) / HBG 450(0) / GPS 4500).
Should an existing master clock (e.g. MTC, CTC, MTS, ETC) be augmented by the
WTD 868-T-V2 wireless time distribution capability, the transmitter can be
synchronised from the DCF output of the master clock.
3.2 NTP Server
The WTD 868-T-V2 reads NTP packets (Network Time Protocol) of a time server on
the LAN. As the transmitter only needs Multicast messages from a time server, no
specific IP address has to be programmed. Only the last part of the Multicast IP
address has to be selected by means of DIP switches. The time server provides the
packet on the following Multicast IP address (administratively scoped IPv4 multicast
address):
239.192.54.nnn (nnn = 1..15, selectable with switches 1 to 4)
The interval, in which the time server emits NTP packets, can be freely selected (e.g.
twice a minute).
3.3 Time Acceptance
For the first synchronisation, the WTD 868-T-V2 requires two valid packets. Later 4
valid packets are required to change the time on the transmitter. This number of
packets is defined, in order to prevent the acceptance of wrong time information.
3.4 Loss of Synchronisation
In the case of a loss in synchronisation, the transmitter will continue to function for an
hour on the internal quartz accuracy. After that time distribution will stop.
3.5 Accuracy
The transmitted time has an accuracy of +/-20ms.
3.6 Time Zone Entry
Internally, the WTD 868-T-V2 functions with coordinated universal time (UTC). In
addition, the transmitter converts the time information received according to the time
source to UTC (NTP and GPS time are per definition UTC and do not require any
conversion). In order to be able to emit local time, the WTD 868-T-V2 requires a time
zone entry for calculating local time offsets. The offset is added to the coordinated
universal time.
3.6.1 Standard time zone table
The transmitter provides a time zone table with 59 standard entries. The desired entry
can be selected with the switches 5 to 10 of the LAN/time settings switch.
If a standard entry is used, switch 11 of the LAN/time settings switch must be in the
OFF position.

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3.6.2 Time Zone Server
It is possible to run a time zone server within the LAN (e.g. Little Time Server LTS),
which provides the WTD 868-T-V2 with up to 15 different time zone entries. The
suitable entry can be selected with the configuration switches 5 to 10 of the LAN/time
settings switch.
The time zone server must use the same IP multicast address as the time server for
distributing the time zone packets. The time zone server normally functions at the same
time as the NTP time server.
If a time zone entry of a time zone server is used, switch 11 of the LAN/time settings
switch must be in the ON position.

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4 Configuration
4.1 Configuration switch
The WTD 868-T-V2 has 2x12 switches, enabling the operation mode to be configured.
It is recommended that settings be carried out on the equipment with the power turned
off. Most settings are binary weighted (see following tables and examples):
4.1.1 Synch. / RF settings switch
Switch 1..2: Selecting the time source:
0: NTP (synchronisation from NTP multicast server)
1: DCF 77 / HBG (local time)
2: MSF
3: GPS (GPS 4500 time signal receiver) DCF 77 (DCF)
Switch 3..6: Setting the transmitter address (0..11).
The selected transmitter address determines the frequency with
which the time messages are transmitted. The periodicity is
determined as follows:
Addresses: Periodicity:
0 1.250 s
1 1.750 s
2 2.250 s
3 2.750 s
4 3.250 s
5 4.250 s
6 4.750 s
7 5.750 s
8 7.250 s
9 10.250 s
10 28.250 s
11 59.750 s
For most installations an address selection between 0 and 9 is
recommended. The addresses 12 – 15 can not be used.
Switch 7..8: Selecting the transmitter power:
0: 0 mW
1: 125 mW
2: 500 mW
(3: 500 mW)
The selection of the transmitter power should be as low as
possible and is to be determined by trials in installing. If need be
the fitting of further transmitters or repeaters is necessary.

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Switch 9..11: Reserved (no function).
Switch 12: Sets the transmitter in initial mode (Init-Bit is set within the
transmitted time message).
ON
1 2 3 4 5 6 7 8 9 10 11 12
Configuration example:
1..2: Time source NTP
3..6: Transmitter address 2 (sends every 2.250 seconds)
7..8: Transmitter power 125 mW
12: Normal mode (Initial mode switched off)
Switch:
Status:
Function:
1 Off Select time source. Significance 0
On Select time source. Significance 1
2 Off Select time source. Significance 0
On Select time source. Significance 2
3 Off Select transmitter address. Significance 0
On Select transmitter address. Significance 1
4 Off Select transmitter address. Significance 0
On Select transmitter address. Significance 2
5 Off Select transmitter address. Significance 0
On Select transmitter address. Significance 4
6 Off Select transmitter address. Significance 0
On Select transmitter address. Significance 8
7 Off Select transmitter power. Significance 0
On Select transmitter power. Significance 1
8 Off Select transmitter power. Significance 0
On Select transmitter power. Significance 2
9 Off Spare
On Spare
10 Off Spare
On Spare
11 Off Spare
On Spare
12 Off Transmitter in normal mode
On Transmitter in initial mode