Data Mailbox Data Limt


I am using DataMailbox to backfill data and have only been able to backfill data for around 4 days and 14 hours. In the SDK I am seeing the that : “If the DataMailbox acts as a temporary storage, there is a limitation in the capacity that can be stored: a point can be stored for 10 days maximum, beginning when it was sent to the DataMailbox”

I am wondering if there are any other limiting factors such as datapoints or storage on the eWON. We have around 150,000 datapoints a day. Is there a limit on the number of datapoints that can be stored in the DataMailbox?

Hello Ryan,

There is also a data point quota that limits you to 5M for free+ and 10M for pro per month.


What request are you using to pull data? If you are using syncdata you might need to check for a moreDataAvailable flag also being returned. This indicated you need to run the call again to get the additional data.

Hi Deryck,

Thanks for the response. We have not hit the 5 million data points for the month (based on the number/ interval of the historic tags we have set up and DataMailbox usage shows 14%). The problem seems to be an internal storage problem because the historic logging table does not have data beyond the past 4 days. Here is a screenshot of the historic logging of one of the tags that has been logging for months, but only has the past 4 days of data.

For the calls, I am using get data, and moreDataAvailable is not true.

Is there an internal memory limit of the EWON for storing historic data? From a few EWONS, it seems like each EWON can store around 1.6 MB of historic data.

On an Ewon Flexy, you can store up to 1.000.000 points. This strongly depends on its memory configuration where the default config allows 250.000 points.

I would not expect this to cause an issue if you are uploading to the mailbox. Unless you are logging more data then the flexy can store before pushing it up to the mailbox.
I would check the ewon data by downloading a full log. you can use this EBD /rcgi.bin/ParamForm?AST_Param=$dtHL$ftT

Hi Deryck,

Ok thanks. So for changing memory allocation, what exactly is /usr? Is there a way to check how much memory /usr is currently taking up? What are the risks of changing the memory allocation so /usr only has 16MB allocated?

Helo Ryan,

The storage configuration of the ewon can be changed under Setup > System > Storage > Memory Settings.

Here you will find the size of the /usr and log file.

What is the storage capacity of the eWON? (

The usr can be used for storying other user accessible files such as files created with EBD’s or custom webpages created with Viewon. Changing the memory organization limits how much of each you can store. It will also reformat the ewon. Keep this in mind if you plan on making a change.