Iotawatt uploader to emoncms error

I have set up the uploader to emoncms. all worked fine for the first few hours then the uploader failed with
Emoncms: Running, Last update 11/18/2022 7:56:10 AM
post failed -11

I have rebooted the iotawatt and deleted and reinstated the uploader to no avail. I still get the error message

-11 is timeout. That would indicate a problem with Emoncms. Are you using or do you have a local instance?

Hi there, thanks for the quick reply. I have a local instance running on a raspberry pi. this appears to be running and I can see the iotawatt inputs in emoncms and these appear to be changing in real time.

And you still have the timeout message? Is the IoTaWatt status display updating? Is the Last Update time advancing?

The last update time is stuck at 7 hours in red which is when everything stopped. sample from emoncms inputs screen

mains voltage [log] 7 hrs 239.72

heatpump supply [log] 7 hrs 2.344

from grid [log] 7 hrs 5.65

solar pv [log] 7 hrs 14.2

The inputs which appeared to be changing in real time are just flipping between two semi random values. I have rebooted the pi to no avail.

the iotawatt is still saying uploader failed -11

Pretty sure this is a problem with your Emoncms instance. Can you try stopping the Emoncms uploader using the stop button in the status display, then start it again?
The message should change somewhat.
I’ve set your forum account so you can upload screenshots.

Without anything else to go on I have to say it looks as if there is a problem with your Emoncms instance. Can you post a screenshot of your IoTaWatt Emoncms setup.?

Unrelated, it looks like you are set to NTP time. Are you in the UK time zone?

Also, you have two mains defined and it looks like 2/3 of a three-phase system. Can you clarify? The Power factor of your solar doesn’t look right and could be a three-phase setup issue as well.

I am in the UK on single phase. the two feeds are just a hangover of some curiosity as to what a spare CT would measure on the other mains tail. Still setting up so there are a few anomalies like that.

will check out the time issue.

inclined to agree that the real issue is with Emoncms but currently in the dark as to what that might be. problems occurred about the same time as I enabled one wire temp probes on the Pi and Emonhub. everything is running on the Pi which is a bit old and may be struggling. The temps look ok though.

not sure which screenshot you are looking for.

It looks like this:

Hi There, taking on board your suggestion that it was probably Emoncms that was the issue I decided to delete all the iotawatt feeds and history taking it back to a clean setup. I then also deleted the uploader and reinstated it using different labels just in case. The idea was to cause Emoncms to start afresh as far as possible. I started the loader running and it successfully ran for a while without error with a bulk send of 5 and send interval of 10. The Emoncms inputs view shows green about once a minute. not entirely sure what this means but was red before so assume its good. Set up new feeds for the iotawatt inputs and these appear to be working also. Have not tried uploading history but will give it a few days of good uploading before I try that. Thanks for your help with this issue, often a hint as to the right pebble in the gravel pile is of the greatest assistance.



I have an update. uploader ran fine until late this afternoon and then expired again with the -11 error again. no clues as to what -11 really means and I am loath to delete everything and start again. basically its not a usable system if it keeps falling over every day or two with a couple of hours needed to recover every time. I am logging several temperature feeds direct in Emonpi and these are working perfectly. The Iotawatt seems to work fine also with its own data but it would be so much better to be able to see the data all in one place. not joy getting the missing history uploaded from the iotawatt either.


The uploader didn’t expire, your WiFi or Emoncms “expired” again. IoTaWatt sends the data out to the URL that you specified. -11 is timeout, meaning that there is no response. The IoTaWatt can only continue to shout out, hoping that there is intelligent life out there on the LAN and that it will respond.

You’re talking about the Pi right?

Can you post the IoTaWatt status display expanding all of the tabs, especially the WiFi tab? Also, please post the recent message log.

I’m not particularly interested, but you might consider looking at any Emoncms logs.

The iotawatt and the Pi are both on hardwired lan. Thanks for the verification as to what the -11 message is. I can also understand that there will be occasions where the two machines lose touch even when they are just 6 inches apart but they should recover without having to delete everything and start over. I too do not think the iotawatt is at fault here but its hard to know for sure. I will will see what the Emoncms forum has to say although I cannot see any useful information in the Emoncms logs.

The IoTaWatt is strictly WiFi only. There is no way to connect it via ethernet.

oops thats a bit embarrassing. everything else is hard wired and I had a brain lapse. does however raise a useful point. I will check the wifi connectivity and see if i can improve it. could well explain why the error occurs in the first place no sure if that explains why once the error had occurred it never recovers. for the future an ethernet port on the iotawatt might be useful ?