UTC based timestamps

As of firmware 13.2 (PR), the eWON Flexy uses UTC timestamps to record its historical data (tag values and alarming). Before firmware 13.2 (PR), these devices used the local time to store historical data.

This is a very neat and useful improvement as it eases the handling of data regardless where it comes from.

But it can also have an impact on existing projects: eWON Flexy or CD running a previous firmware would be using local time timestamps and others would be using UTC timestamps.
In terms of data logging, we see that it could be difficult to handle the backward compatibility.

UTC or local time timestamps

As of firmware 13.2s0 PR, we introduce the possibility to:

  • continue using the local time as time reference.
  • switch to the new model and start using in UTC.

The selection of the method how your Flexy handles the timestamps is based on a checkbox available in the System Wizard and in the settings of the date & time of your Flexy.

The default behavior of the firmware 13.2s0 (PR) is to continue exporting data in local time. Therefore, by default this checkbox is unchecked.

The choice to continue using local time or to switch to UTC timestamps would depend on your situation.
Our recommendations are the following ones:

  • Your Flexy is integrating a new project or is used as standalone:
    • Check the box to use UTC-based timestamps.
  • Your Flexy is integrating or replacing another eWON for an existing project:
    • Leave the box unchecked to continue using local time

We also created a KB-0284-00: UTC timestamp logging that explains how your eWON behaves based on your choice.