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Data loss following powercut

Posted: Thu 23 Sep 2021 3:10 am
by MarkinNZ
Hi
Please help.

problem
We had a powercut today and the Raspberry PI 4 running CumulusMX shutdown untidily. I restarted it and CulumusMX. All was looking good until
" - Downloading entire logger contents!" x 2.

Looked OK, but when I went to website I watched the rain gauge reverse from 26mm of rain today down to 0.

Where has my data gone?
How do I get it back?
What else has gone?

Can someone please help me get my data back.

I've attached log files.

I have a Davis Vantage Vue with WIFI logger to collect the data. I upgraded CumulusMX today so using v.3.13.3 build 3148.

Background
Two days ago I converted to CumulusMX. I've done a couple of youtube videos on Linux so my knowledge is limited to copying files about. I was pretty pleased with myself for getting CulumusMX running on the PI :D I have lots of computer experience but all Windows based. We're in COVID lockdown and I thought it a useful exercise to learn Linux - hence the PI.

Re: Data loss following powercut

Posted: Thu 23 Sep 2021 8:47 am
by mcrossley
Your log file shows that the last data logged by CMX was on 9/23/2021 13:36:09.
Did you do another run of CMX after the power outage before this one?

When it requests the data from the station logger at 13:36, the last logged value was recorded was 9/23/2021 13:00:00, so the 13:15 and 13:30 log entries are missing. That is why the entire logger contents are downloaded. (the Davis loggers send the entire contents if the date/time requested is not found in its memory).

You say you have a WiFi logger, I guess that unlike a Davis logger that device needs external power to function? So if you had a power outage the station will also stop logging data? I'm not sure what effect that has on the console itself - anyone know?

Once it had downloaded the logger contents (twice - that is normal), it tried to start the loop data, that worked for a while, then the 26th message of the 50 requested errored at the network level (that is probably the "normal" WiFi logger unpredictable behaviour). CMX tried to reconnect to the station, that succeeded, but that CMX was then shutdown a minute later.

So I think everything was working as expected, it may require a correction of your rainfall for today because of the outage and data loss.


What you could do is restore your data files back to the last midnight backup (with CMX stopped of course).
It should then catch up from the logger and just have a gap over your power outage, and you would not need to apply any corrections.

Re: Data loss following powercut

Posted: Thu 23 Sep 2021 1:41 pm
by PaulMy
You say you have a WiFi logger, I guess that unlike a Davis logger that device needs external power to function? So if you had a power outage the station will also stop logging data? I'm not sure what effect that has on the console itself - anyone know?
The WiFiLogger, just like the Davis WeatherlinkIP or USB/Serial loggers, resides in the Davis Vue or VP2 console. As long as the console has batteries, when the power goes out the console will keep on displaying from the ISS as usual and the WiFiLogger will continue to do the logging.

Enjoy,
Paul

Re: Data loss following powercut

Posted: Thu 23 Sep 2021 2:45 pm
by mcrossley
Thanks Paul - I guess no, or low batteries then?

Re: Data loss following powercut

Posted: Fri 24 Sep 2021 12:58 am
by MarkinNZ
Thank you Paul, et al. I was worried that if I restored that the data would not be updated from the weather station.

I restored as at a couple of days ago. When I ran the app I got the date / time issue, so I ran again specifying en-NZ as the language and it ran, downloading data and updated as expected (hoped!!!).

So, issue resolved and lessons learned. Thank you.

FYI the wifilogger details are here: https://wifilogger.net I have WiFiLogger 2. It is installed in the Davis console and transmits data via wifi network. It is powered by the console, so is powered battery when the mains power is out.

cheers

Mark