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FAQ: Difference between revisions
Cumulus takes a long time to download the data from my Davis station at start up
(How does Cumulus know the height of the cloud base?) |
(Cumulus takes a long time to download the data from my Davis station at start up) |
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==How does Cumulus know the height of the cloud base?==
It doesn't. It uses a calculation which gives the theoretical height above ground level at which Cumulus clouds might form, based on the current temperature and dew point. It assumes that the difference between temperature and dew point decreases by about 4.4 degrees Fahrenheit per 1000 feet increase in altitude. When the two values coincide, the air is saturated (relative humidity = 100%) and Cumulus clouds may form.
==Cumulus takes a long time to download the data from my Davis station at start up==
When Cumulus starts, it asks the station for all the data from the logger since the last time it was running. If the timestamp that it supplies does not exactly match the timestamp of an entry in the Davis logger, the station has a strange 'feature' where it decides to send the entire contents of the logger. This will take some time to download, during which the Davis console display will appear freeze.
It is recommended that you set the logging interval in Cumulus to the same interval as the station, then Cumulus will be able to make sure it uses a timestamp that matches an entry in the logger.
=Troubleshooting=
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