Just upgraded from emonSD-26Oct17 to 21Jul21 using standard export/import (not using the direct SC card transfer). A simple input from emonPi(V1) power2 declared as a feed constantly refreshes properly on the feeds screen table (states FIXED (5s), but I understand that 21Jul21 only updates at 10s). The feed is used in 2 visualisation multigraphs embedded into a dashboard. Every 4 minutes the feed stops, removes the previous 4 minutes of data on the multigraphs and starts again. Is this anything to do with the original 5s update now being 10s? Any suggestions as to what I could do to fix this issue? 2 screen shots attached showing issue. Also attached is the log which I do not understand but appears to match the issue.
A second issue is the update time. I used node red to drive a Smart EVSE charger, but the original 5s update was too slow to provide feedback and allowed the charge current to exceed requirements. The emonPi team were really helpful and so in 2016 they provided a patch that allowed for a 1.5s update on the 2 emonPi inputs - worked fantastically for 10 years! The patch does not work on 21Jul21 and the emonPi team are unable to help. Has anyone patched 21Jul21 to decrease the sample rate? This solution is excellent for me as it controls charging at 11kW single phase whereas the best solar aware chargers I can find are only 7kW single phase.
Is this @glyn.hudson & @TrystanLea, because I think they - Trystan in particular - are the likeliest who will be able to help you.
You could have a VITS (Variable Interval Time Series) Feed running at a 1.5 s update rate if you configure the “Emon” front end of your emonPi to do so (it might mean hard coding it because I can’t remember if the July 21 version allows you to change it via emonCMS), but I don’t know what else you need to get the data to your EV charger.
Thank you for the reply; as you surmised it was Glyn that assisted my original Node Red development. It is Node Red that gets the data to the Smart EVSE unit. I am still attempting to download and install Node Red into the 21Jul21 release.
I am unsure if I have properly fixed the constantly refreshing feeds - I read that a file involved with the feeds (PHPFina.php as per the log) described as (ID number).dat needed to be deleted, but without the skills required I could not even find such files in emonpi using terminal and the find command. So rather than continue this somewhat risky endeavour (for me!) I simply created additional feeds and I am now using these having re-selected these in the visualisations. Will the original failed feeds end up corrupting the system if not deleted properly?
I assume you have tried to delete the Feed via the Feeds page, and that you do not have that Feed being written to anywhere else, most likely in the Input processes?
The .dat files are at var/opt/emoncms/phpfina - likewise var/opt/emoncms/php/phpfiwa and var/opt/emoncms/phptimeseries for the other Feeds’ data files.
The way I found them is first, I mounted the SD card (actually, an old one) on my laptop, and the data files are in the 3rd partition.
Then mount in the RPI showed the mount point of that partition (/dev/mmcblk0p3) as being /var/opt/emoncms. And that is the parent folder of the 3 data file directories.
The answer to the next question is No, I’ve never found this documented anywhere, and I don’t know why.
I think the Feed file won’t cause trouble if it is not written to, except it will consume space on the SD card. But before you delete it (outside emonCMS), make absolutely certain it is not referenced anywhere - in any Input processing, visualisation, dashboard, graph etc.
I know nothing about Node Red so I can’t help you there.
