S
YSTEM
6844(RC)
S
YNCHRONIZATION
System 6844(RC) - V03.00
29 / 157
hopf
Elektronik GmbH
Nottebohmstr. 41
• D-58511 Lüdenscheid • Tel.: +49 (0)2351 9386-86 • Fax: +49 (0)2351 9386-93 • Internet: http://www.hopf.com • E-Mail: [email protected]
The use of the DCF77 signal means that the system, in principle, is synchronized with local
time (standard time with ST/WT changeover, if required). Certain points must be noted in or-
der for the system to transmit both local time and UTC time correctly.
In this synchronization mode the UTC time is a calculated time which is
determined on the basis of the time offset and changeover points of time for
summer time and winter time.
The DCF77 Transmitter (location: Mainflingen, Frankfurt am Main / Germany) always trans-
mits time information as local time (CET/CEST). This means that
UTC time is calculated
for
DCF77 systems. Two variables are now required in order to convert from local time to UTC
time:
o
The time offset between UTC and the valid standard time (winter time) in the
respective time zone
o
The changeover points of time between winter time and summer time
– pro-
vided that such changeover takes place in the respective time zone
The signal received via the DCF77 antenna contains this required information for the CET
time zones (UTC+1h).
As a result, when configuring, it is necessary to differentiate between system operation in the
CET time zone and system operation as a slave or Sub-Master system for worldwide appli-
cation.
2.1.4.1 Operation in the CET Time Zone (Europe)
If the system is configured for operation in the CET time zone, settings for time offset and
changeover points of time are not required or are ignored, since the time offset is fixed and
the DST changeover is controlled by information contained in the synchronization signal.
Fixed
time offset
:
Standard time (winter time)
UTC + 1h
Daylight saving time
UTC + 2h
Changeover point of time + current time status
(summer or winter time)
are taken from the synchronization signal
2.1.4.2 Operation in a different Time Zone (Worldwide)
If the system is configured for worldwide application, in order for UTC time output to be cor-
rect, the time offset must be parameterized for the respective time zone. Settings for the
changeover points of time are not required, or are ignored, since the DST changeover is
controlled by the information contained in the synchronization signal.
Time offset
: Standard time (winter time)
Set time offset
Daylight saving time
Set time 1h
Changeover point of time + current time status
(daylight saving time or
standard time) are taken from the synchronization signal
