Meinberg GPS164/AQ/AHS, Руководство по эксплуатации

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DCF77 emulation
The GPS164xHS satellite controlled clock generates time marks which are compati-
ble with the time marks spread by the German long wave transmitter DCF77. If
configured in GPSMON32, these time marks are available as pulse outputs. In
addition, an AM-modulated carrier frequency of 77.5kHz is available via a BNC-
connector in the front panel. This signal can be used as a replacement for a DCF77-
antenna.
The long wave transmitter installed in Mainflingen near Frankfurt/Germany trans-
mits the reference time of the Federal Republic of Germany: time of day, date of
month and day of week in BCD coded second pulses. Once every minute the complete
time information is transmitted. However, GPS164xHS generates time marks repre-
senting its local time as configured by the user, including announcement of changes
in daylight saving and announcement of leap seconds. The coding sheme is given
below:
Time marks start at the beginning of new second. If a binary "0" is to be transmitted,
the length of the corresponding time mark is 100 msec, if a binary "1" is transmitted,
the time mark has a length of 200 msec. 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.