Topic: [WeeWX] average or instant data?

[sheldon]

Hi guys,
I'm interested in understanding how weewx handles row data coming from the station (in particular, from a davis vp2 station), id est every 2.5 secs data packets.
Are the data written in "weewx.sdb" average or instant data?
Let me do an example: I've set the data archive to 5 mins, so in weewx.sdb I have rows temporally separated by 5 mins. Are the temperature data I see the instant data, catched in that exact moment, or the average values in those 5 mins? I know that Davis station sends temperature data every 10 secs, so in 5 mins weewx should have received 5 values, and so it would be intresting knowing the average of these data. This would make more sense for wind data: if the data archived are just the instant, many many packets would be lost, while the average wind data in those 5 mins is a precious information.
I hope I explained well the question...
It would be interesting knowing else what Weatherlink software does with row data, because the 5 mins archive is quite similar to weewx' one.
let me know and thank you

[galfert]

For Davis stations WeeWx polls the console every 1 second. Weewx commits to archive data the average of the logging period interval. If you see data logs with 5 minutes then that is the average of that time period.

For wind gusts.. Better to read this answer
https://github.com/weewx/weewx/wiki/windgust

[sheldon]

For Davis stations WeeWx polls the console every 1 second. Weewx commits to archive data the average of the logging period interval. If you see data logs with 5 minutes then that is the average of that time period.

For wind gusts.. Better to read this answer
https://github.com/weewx/weewx/wiki/windgust

but it isn't written anywhere that the shown values are average values of 5 mins intervals. How can you be sure?
And what about weatherlink? in the "browse" section you can see data every 5 mins (or the interval set by the user). They are shown this way: value, max and min value (during the 5 mins): so it seems that the value reported is the instantaneous value catched in the moment of writing the line in the datalogger. Isn't it? And, finally, what about wind in weatherlink?

[galfert]

From:
http://www.weewx.com/docs/customizing.htm

Archive records
By contrast, archive records are highly regular. They are generated at regular intervals (generally every 5 to 30 minutes), and all contain the same data types. They represent an aggregation of the LOOP packets over the archive interval. The exact kind of aggregation depends on the data type. For example, for temperature, it's generally the average temperature over the interval. For rain, it's the sum of rain over the interval. For battery status it's the last value in the interval.

Some hardware is capable of generating its own archive records (the Davis Vantage and Oregon Scientific WMR200, for example), but for hardware that does not archive data, WeeWX generates them.

It is the archive data that is put in the SQL database, although, occasionally, the LOOP packets can be useful (such as for the Weather Underground's "Rapidfire" mode).

From that explanation it seems that in the case of Davis, the station console does its own averaging and logging and WeeWx accepts it.


From:
http://www.weewx.com/docs/usersguide.htm

tcp_send_delay

How long to block after sending a socket packet to the WeatherLinkIP. Default is 1 second.