If your one loop packet was the only loop packet received by WeeWX in that archive interval then the archive record that WeeWX would synthesise from that solitary loop packet would be the same as that loop packet. If as you said that loop packet was stored by hardware and if the driver's genArchiveRecord() method obtains that same data when it generates an archive record, then yes they will be the same. Highs and lows in the daily summaries would be the same but it would not surprise me if some timestamps were different. Loop packets are generally timestamped when the data is read, whereas archive records are typically timestamped at the end of the period they cover. So for an archive interval that covers say 11:05:00am to 11:06:00am, the loop packet may have been created at 11:05:25am and timestamped accordingly. If WeeWX is set to obtain highs and lows from loop packets (ie loop_hilo <http://weewx.com/docs/usersguide.htm#StdArchive> is True) then if a new max/min is found in that loop packet the relevant timestamp recorded in the daily summary will be the loop packet timestamp. If you now consider the archive record that is read during a backfill, it will be timestamped 11:06:00am, again any new highs or lows will be recorded (so the actual aggregate value will be the same) but in this case the timestamp recorded for the high or low will be the archive record timestamp 11:06:00am. If you happen to have more than one loop packet in the archive period then you may loose some fidelity of the actual observation high/low value as well.
This is the same effect you see if you rebuild your daily summaries with wee_database --rebuild-daily, if you have loop_hilo = True then your daily summary tables will likely have loop packet timestamps for many highs and lows but after you rebuild the daily summaries you loose that fine detail and your high/low timestamps will align with archive record timestamps. If you have multiple loop packets in an archive interval then your high/low values may be one of the values in those loop packets, after rebuilding though you end up with archive values being used to generate the highs and lows which are typically averages of loop values. For example, if you have four loop packets in an archive interval and each has an outTemp value of 8.0, 9.0, 12.0 and 7.0 degrees C your daily summary may record 12.0 as the max. The corresponding archive record outTemp value would (8.0+9.0+12.0+7.0)/4=9.0 so your max might be 9.0. Gary On Tuesday, 9 February 2021 at 21:03:10 UTC+10 michael.k...@gmx.at wrote: > > If you mean does WeeWX determine if any incoming archive record has (for > example) a new daily max for some field and then save that data, then yes > that is what StdArchive does. > > So if a hardware sends a loop packet with all the readings in a > one-minute-interval, and stores these exact values in its own storage in a > separate entry, one entry per minute, the weewx database values are exactly > the same, regardless if they were received as loop data as if they were > backfilled? Including timestamps and Values for min/max in > archive_day_xxxx, which may differ from the min/max value found in all > weewx archive records of that particular day, with timestamps between > possible timestamps of archve values? > > -- You received this message because you are subscribed to the Google Groups "weewx-development" group. To unsubscribe from this group and stop receiving emails from it, send an email to weewx-development+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/weewx-development/8649044a-1417-4c9b-b41b-6e4fe4bd2d8en%40googlegroups.com.
