connectionS and PortS
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DEWE3-M4 • Technical reference • Printing version 1.0.1 • August 25, 2022
GPS
(optional)
The DEWE3-OPT-GPS function is an optional feature and provides the following synchronization input modes:
GPS specifications
Synchronization input modes
GPS
Supported GNSS signals
GPS/Glonass/BeiDou/QZSS
PPS accuracy
100 ns
Refresh rate
1 Hz, 5 Hz, 10 Hz
Position accuracy (horizontal CEP)
–
Autonomous
–
Differential
INFORMATION
CEP 50 %, 24 h static, roof antenna
<2.5 m
<2.5 m
Input connector GPS
SMA for GPS antenna
Tab. 10: GPS specifications
DEWE2/3 clock engine
The DEWE3-A4 is designed for continuously measuring data, even if the external time base source is temporarily not
available. Especially in GPS mode that could easily happen. Reason for that is the weather sensitive GPS reception.
One cloud might be enough to interrupt the synchronization for a while. In that case the TRION-TIMING-V3 generates
a notifying event and continues measuring on its internal time base. This internal time base has been adjusted to the
external reference while the sync was stable.
That minimizes the drift in free-run mode. Typically it is far below 1 ppm. Only when the environmental conditions
change dramatically during a longer non-synced period of time, it might go up to a maximum of 10 ppm.
When the synchronization has established again the TRION-TIMING checks if the internal time base error is still below
the pre-programmed restart limit. If yes, it starts resyncing by slightly changing the time-base until the time stamps
matches again exactly. That prevents from gaps in the data file due to resync. That might take a while because the max
-
imum readjusting speed is 100 ppm. If for some reason a hard resync is needed the restart limit could be set to a low
value. In that case the datafile will be interrupted.
Fig. 14: Gapless recording
