FUNKUHREN
Technical Information
Operating Instructions
DU35K
Impressum
Werner Meinberg
Auf der Landwehr 22
D-31812 Bad Pyrmont
Phone: ++49 52 81 - 9309-0
Fax: ++49 52 81 - 9309-30
Internet: http://www.meinberg.de
Email: info@meinberg.de
September 3, 2004
Inhaltsübersicht
General Information about DCF77 ...................................................... 5
Features of the DU35K ........................................................................ 6
Installation............................................................................................6
Power Supply.............................................................................. 6
DU35K as Stand Alone Clock ............................................................. 7
DU35K as Slave Clock ........................................................................ 7
Synchronisation by serial Time Strings:..................................... 7
Synchronisation by Pulses per Minute: ...................................... 7
DU35K as Radio Clock........................................................................ 8
Mounting the Antenna ................................................................ 9
Usage of the Buttons MENU and SET .............................................. 10
The Menus in Detail ................................................................. 10
Time & Date.................................................................... 10
Language ......................................................................... 10
Brightness........................................................................ 10
Daylight Saving............................................................... 10
Winter/Summer Changeover........................................... 11
Summer/Winter Changeover........................................... 11
Exit .................................................................................. 11
Rear View DU35K............................................................................. 12
Rear Panel Connectors.............................................................. 13
CE Label ............................................................................................ 13
Connection Exaples............................................................................ 14
Pin Assignments of SUB-D Connector IN ............................... 16
Pin Assignments of SUB-D Connector OUT ........................... 16
Technical Specifications: ................................................................... 17
Format of the Meinberg Standard Time String ........................ 18
Jumper Arrangement.......................................................................... 19
General Information about DCF77
The radio remote clocks made by Meinberg receive the signal from the long wave
transmitter DCF77. This long wave transmitter installed in Mainflingen near Frankfurt/Germany transmits the reference time of the Federal Republic of Germany. This
time reference is either the Central European Time (Mitteleuropäische Zeit, MEZ) or
the Central European Summer Time (Mitteleuropäische Sommerzeit, MESZ). The
transmitter is controlled by the atomic clock plant at the Federal Physical Technical
Institute (PTB) in Braunschweig/Germany and transmits the current time of day, date
of month and day of week in coded second pulses. Once every minute the complete
time information is available.
At the beginning of every second the amplitude of the high precision 77.5 kHz
carrier frequency is lowered by 75% for a period of 0.1 or 0.2 sec. The length of these
time marks represent a binary coding scheme using the short time mark for logical
zeroes and the long time mark for logical ones. The information on the current date
and time as well as some parity and status bits can be decoded from the time marks of
the 15th up to the 58th second every minute. The absence of any time mark at the 59th
second of a minute signals that a new minute will begin with the next time mark.
Our radio remote clocks decode the highly accurate information on date and time
within a wide range around Germany. So some of our clocks are installed in Bilbao/
Spain as well as in the city of Umeå in northern Sweden - fully satisfying the
requirements of the users. The radio remote clocks automatically switch to summertime and back. The reception of the time information is free of charge and does not need
to be registered.
Generally it is important to position the antenna in an optimal way. It should be
mounted at least 30 centimeters away from the clock unit and from solid steel. The
antenna should be aligned at a right angle to the direction of the transmitter (Frankfurt).
Figure: Decoding Scheme
P
8
3
M
4
Year of the Century
Month of Year
Day of Week
Day of Month
0
0
2
0
1
0
8
4
2
1
1
0
50
8
4
2
1
4
2
1
40
0
2
0
1
8
4
2
1
0
30
2
0
P
2
0
1
Hour
P
8
1
1
4
2
(reserved)
10
R
A
1
Z
1
Z
2
20
A
2
S
1
2
4
8
1
0
2
4
0
Minute
0
M Start of Minute (0.1 s)
R RF T ransmission via secon dary antenna
A1 Announcement of a ch ange in dayligh t saving
Z1, Z2 Time zone identification
Z1, Z2 = 0, 1: Daylight saving disabled
Z1, Z2 = 1, 0: Daylight saving enabled
A2 Announcement of a lea p second
S Start of time code information
P1, P2, P3 Even parity bits
5
Features of the DU35K
The large display DU35K is a 50mm hight LED matrix display that shows time and
date in three lines with eight characters each as follows: day of week, day of month,
month, hours, minutes and seconds. It is available as a free running stand alone clock,
as a slave clock or as a radio clock with integrated DCF77 receiver.
Fig.1:
Front View
The DCF variant provides automatic changeover of daylight saving. In case of
supply voltage failure the on board RTC keeps the time based on XTAL for at least 10
years. The language displayed can be choosen. The wall mounted housing of the
DU35K is made of plastic coated steel sheet.
The power connector, the antenna input and the RS232/20mA interfaces provided
by DU35K are accessible via connectors in the rear panel of the case.
Installation
P ow er Suppl y
The requested supply voltage of 230V/50Hz is applied via the power cord receptacle
in the rear panel. After connecting the power cord and the antenna (only DCF variant)
the system is ready to operate. Time and date become visible on the display.
6