Yes. This is potentially even more of a problem if you only determine whether the sun is shining when the radiation value changes, which is what I now do (with a timeout to deal with the instances when the 'gap' is a multiple of 50+ seconds). I have addressed it slightly differently - I accumulate seconds of sunshine and the total seconds elapsed between computations in the LOOP code and use the *ratio* of these (for each archive interval) to determine sunshine time for that interval.
On Friday, June 10, 2022 at 10:40:09 AM UTC-4 [email protected] wrote: > The Davis VP2 archive are recorded in the datalogger at the exact archive > interval. > So even if for any reason a service bound to NEW_ARCHIVE_RECORD is running > a little bit later that the time the record was captured by the VP2, the > data will still be valid, and the "*event.record['interval'] " *will be > the interval between the two last recors received from the VP2. > > Concerning our context of doing sunshine duration measurements based on > LOOP packets, these loop packets may be not always in phase with the > archive at the time an archive record is processed by weewx for our service > So for instance, I saw initially with my archive interval of 5 min and > during a period of full sunshine, that the sunshine duration derived from > loop packets during an "archive" interval" was a little bit higher that 5 > min, or sometimes a little bit lower : > > 2022-06-06 11:30:19 weewx[4501] INFO user.sunduration: Sunshine duration > from loop packets = 5.016667 min, last radiation = 828.000000, and last > threshold = 639.982068 > > Given the context of "slow" update of solar radiation of the VP2 compared > to the LOOP interval, I decided to round up the sunshine duration to full > minutes > > Le 10 juin 2022 à 15:52, 'Peter Fletcher' via weewx-user < > [email protected]> a écrit : > > Thanks to all! Granted that you are most likely to need to know the > archive interval in the context of an archive interrupt service, where it > is easily available and the returned value is reliable, it would be nice if > the actual working value (rather than just the value from weewx.conf) were > readily available in other contexts. > > On Friday, June 10, 2022 at 9:04:06 AM UTC-4 [email protected] wrote: > >> "Using the interval field from the current archive record should always >> give the correct value.". >> >> I use it in my extension and it works very well: >> *event.record['interval'] * >> >> Le vendredi 10 juin 2022 à 05:04:45 UTC+2, gjr80 a écrit : >> >>> Whilst in almost all cases the archive interval used by WeeWX will match >>> the archive_interval config option in weewx.conf [StdArchive] this is >>> not always the case. Installs that use software record generation always >>> use an archive interval that matches the archive_interval config >>> option; however, when using hardware record generation if the archive >>> interval set in the station hardware is different to the >>> archive_interval config option the archive_interval config option is >>> ignored and the station hardware archive interval is used instead. This is >>> most commonly seen with Davis stations used with a default WeeWX install. >>> The Davis station uses an out-of-the-box 30 minute archive interval and >>> that value overrides the default WeeWX archive interval of five minutes. >>> >>> Using the interval field from the current archive record should always >>> give the correct value. >>> >>> Gary >>> >> > -- > You received this message because you are subscribed to a topic in the > Google Groups "weewx-user" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/weewx-user/W0jG1kElJ1k/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/weewx-user/87e7270c-2cbf-4438-a60b-638be2005049n%40googlegroups.com > > <https://groups.google.com/d/msgid/weewx-user/87e7270c-2cbf-4438-a60b-638be2005049n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > > > -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/weewx-user/d030a216-4cfd-4df3-ad3c-55ae8df63cf8n%40googlegroups.com.
