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Run-away values kwh?

I’m getting power (Watt) readings from my Iotawatt. i’m using the inputs to also make a kWh feed from these.
Howerer sometimes the kWh feed is “running away”. By this i mean: it jumpes from ex. 2000 kWh to 2.1425e14kWh and when i try to view it it says that there is an error with the data.
I encountered this a third time now, with sometimes the same feeds and sometime others (yesterday 6 feeds were bad).
I recalculated them with postprocessing (with a different feed name) and deleted the bad one.
Any idea’s how they are going bad?

Hello @promy, are you using the power to kWh input process to create the kWh feeds?

Yes, i am. First a “log to feed” and then a “Power to kWh”.
I checked the “log to feed” feed and i could not really find something that would explainit.(no big spikes in the graph).
I already deleted the “wrong” Kwh feeds unfortunately

Thanks @promy, did you zoom in on the log to feed feed at the point of the jump in the kWh feed?, it’s easy to miss short spikes with a quick browse through a feed. If it happens again it might be worth double checking that. That’s the obvious mechanism that I can think of as there isn’t any filtering of very high values in the power to kWh input process.

I see this sometimes as well with the accumulator processes.

@TrystanLea : when scrolling through the power (watt) feed, i found an error: " Request error: Received data not in correct format. Check the logs for more details". The graph will not show me a couple of minutes.
The log at the admin page shows “2021-04-18 18:58:35.424|ERROR|index.php|json_encode - feed: Unknown error” (this is for the time i try to graph it).
The file (/var/log/emoncms/emoncms.log) is not bigger than whats showing on the admin page.
Any idea’s whats going wrong, and how to prevent the Power to Kwh from doing this again?

Hello @promy I’m not sure what is causing the issue unfortunately so not sure where to start with fixing it or preventing it from happening in the future. I need to find a way of replicating the issue so that I can then check that the fix does fix the issue.

Are you recording the data using PHPFIna?
is it an emonSD system running on a Pi?
Would you be able to copy and paste the system information from the admin page here?

@TrystanLea : Thanks for the support!. yes, its a raspberry pi running the low-write 10.2.6 version with PHPFina.
What info would you like?

Update: i had a look at the graphs on my Iotawatt and on the influxdb i’m also sending the data to.
The iota cannot graph that specific interval (2 minutes or so), it crashes.
The influxdb is als showing missing info.

So my best guess would be that there was some bogus data being send to the emoncms. All of the affected feeds are linked to that Iota, only 1 feed was not affected…

Thanks that all useful to know. It might be worth trying the ‘Max value allowed’ input process placed before the ‘Power to kWh’ process. If you set the max value to the maximum you would expect on each CT input that should clip any large values that sounds like they are not being transferred or decoded properly. I will try to see if I can work out a mechanism that might be causing this.

Thanks. I added the “max value allowed” to 2 of the 8 feeds that failed last time. This way i can still see the failure and see if it helps. If it happens again i’ll post the update (could be a couple of months)

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Thanks @promy