Meinberg GPS161 - Manual (Page 8)

8
Oszillator options
To realize various requirements concerning the accurracy of the frequency outputs,
the module GPS161 may be equipped with different master oscillators. They are
disciplined by the GPS-system for compensation of long term effects like aging and
temperature dependant drift. However, phase locking of the standard frequency to the
pulse per second (PPS) is only available with the oscillator option ‘OCXO MQ’ or
‘OCXO HQ’. The specifications for the different oscillators can be found in chapter
‘Technical specifications GPS161’. A label on the board shows the oscillator
option of the present GPS161.
Time zone and daylight saving
GPS system time differs from the universal time scale (UTC) by the number of leap
seconds which have been inserted into the UTC time scale after GPS has been initiated in
1980. The current number of leap seconds is part of the navigation message supplied by
the satellites, so GPS161´s internal real time is based on UTC.
Conversion to local time including handling of daylight saving year by year can be
done by the receiver´s microprocessor if the corresponding parameters are set up with the
help of the software GPSMON32 (included Windows software).
Pulse outputs
The pulse generator of the satellite controlled clock GPS161 generates a high- and a low-
active pulse per second (PPS) with a pulse duration of 1msec, which are available at the
contact strip. The turn-on slope of these pulses is phase aligned to UTC-second.
Standard frequencies
The module GPS161 provides two frequency outputs of 10 MHz which are derived
from the master oscillator of the board. If oscillator option ‘OCXO MQ’ or ‘OCXO HQ’
was equipped, these standard frequencies are phase locked to the pulse per second. A
TTL- and a sinewave output are available at the contact strip.