Meinberg PZF600 - Manual (Page 23)

23
DC and AM Timecodes
DC-Level Shift Codes (PWM-signal) B00x and modulated sine wave carrier B12x are
always generated simultaneously. Both signals are provided at the VG64-Connector, i.e.
if code B132 is selected per menu, also code B002 is available. This applies for the codes
AFNOR NFS 87-500 and IEEE1344 as well.
The TFOM field in IEEE1344 code is set dependent on the 'already sync'ed' character
('#') which is sent in the serial time telegram. This character is set, whenever the
preconnected clock was not able to synchronize after power up reset. The 'time figure of
merit' (TFOM) field is set as follows.
Clock synchronized once after power up : TFOM = 0000
Clock not synchronized after power up : TFOM = 1111
Sine Wave AM Output
The amplitude-modulated carrier is available at the VG-connector pin 14a. The carrier
frequency is 1kHz (IRIG-B). The signal amplitude is 3V
pp
(MARK) and 1V
pp
(SPACE)
into 50
Ω. The encoding is made by the number of MARK-amplitudes during ten carrier
waves with the following agreements:
a) binary "0" : 2 MARK-amplitudes, 8 SPACE-amplitudes
b) binary "1" : 5 MARK-amplitudes, 5 SPACE-amplitudes
c) position-identifier : 8 MARK-amplitudes, 2 SPACE-amplitudes
PWM DC Output
The pulse width modulated DC signals shown in the diagramms "IRIG" and "AFNOR
standard format" are coexistent to the modulated output and is available at the VG
connector pin 13a with TTL level.
DCF77 Emulation
The correlation receiver PZF600 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 PZF600 generates time marks representing always the