Meinberg LANTIME, Operating Instructions Manual

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Features of PZF5xx
The PZF5xx is a high precision receive module for the DCF77-signal build in euro
card size (100 mm x 160 mm).
The micro controller of the system correlates its receiver-PZF with the incoming
pseudorandom sequence and decodes the time information of the DCF-telegram
simultaneously. The controller handles input and output functions of the PZF5xx and
synchronizes the internal real-time clock.
By evaluating the pseudorandom phase noise, the PZF5xx is able to generate time
frames with thousand times the accuracy of standard AM-time code receivers. The
precise regulation of the main oscillator (TCXO, OCXO optional for higher accuracy)
of the radio clock is possible therefore. So, the PZF5xx can be used as a standard
frequency generator besides the application as a time code receiver. Six fixed and one
settable TTL-level standard frequencies are available at the rear VG-connector. The
synthesizer frequency exists as an open drain output and a sine wave signal also.
The PZF5xx delivers TTL-low and TTL-high active pulses per minute and per second
further. To distribute information concerning date, time and status, two independent
serial interfaces (RS232) are used which are configurable in a setup menu.
Like mentioned before, the PZF5xx includes a battery-backed real-time clock which
runs crystal-precise if the main power supply fails.
Important system parameters are stored in a battery-backed (RAM of the RTC) or
non-volatile (EEPROM) memory.
If an update of system software becomes necessary, the new firmware can be loaded
via serial interface (COM0) without removing the PZF5xx for inserting a new
EPROM.
Antenna
The PZF5xx operates with a ferrite antenna which is damped to match the
bandwidth needed for the correlation reception.
Assembly of antenna
The antenna has to be mounted as exactly as possible. Turning it out of the main
receive direction will result in less accurate time frames. The antenna must be placed
in longitudinal direction to the DCF-transmitter (Frankfurt). The nearness to
microcomputers should be avoided and the antenna should be installed with a
minimum distance of 30cm to all metal objects, if possible. A distance of several
meters to TV- or computer monitors must be kept.
After switching the PZF5xx to the menu 'PZF STATE', the adjustment of the antenna
can be executed. The displayed value is proportional to the received field strength.
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