Meinberg PZF510 - Manual (Page 14)

14
Frequency synthesizer
The synthesizer of the PZF510 generates a frequency in the range of 1/3Hz to
9.999MHz, which can be set in the menu 'SYNTH.'. The synthesizer-output is availa-
ble with TTL-level, as a sinewave signal or an open drain output at the VG-connector.
The frequency to be generated can be adjusted by giving the four digits of highest-
order, lower significant digits are set to zero. Only the fractions xxx.3Hz, xxx.5Hz and
xxx.6Hz are allowed in the Hertz-range. Frequencies of xxx.3Hz or xxx.6Hz lead to a
periodic fraction, that means to correct 1/3Hz or 1/6Hz, often used by ripple control
systems.
Up to a value of 10kHz the synthesizer is phase-locked to the pulse per second. The
accuracy of this frequency reaches the exactness of the standard frequencies therefore.
Higher frequencies than 10kHz have a maximum error of +/- 2,35 mHz.
The behaviour of the synthesizer after power-up is selectable (see menu 'SYNTH.
M'). Frequency generation can start either directly after reset or after synchronization.
DCF77 emulation
The correlation receiver PZF510 generates TTL level time marks (active High) which
are compatible with the time marks spread by the German long wave transmitter
DCF77. This long wave transmitter installed in Mainflingen near Frankfurt/Germany
transmits 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. The PZF510 generates time marks representing always
the DCF-time including announcement of changes in daylight saving and announcement
of leap seconds, changing the timezone in the setup menu has no effect on the generation.
The coding sheme is given below:
M Start of Minute (0)
R RF Transmission via secondary antenna (0)
A1 Announcement of a change in daylight saving
Z1, Z2 Time zone identification
Z1,Z2 = 0,1: Daylight saving disabled
Z1,Z2 = 1,0: Daylight saving enabled
A2 Announcement of a leap second
S Start of time code information (1)
P1, P2, P3 Even parity bits