Power Chart missing "important" values?

Ignition
,
1

Hi all,

Some of our users have noticed some missing values of interest while using the power chart.
Here’s an example: on the 10th, there’s a large drop in the value of this tag:

Screen Shot 2021-09-13 at 12.14.37 PM
Screen Shot 2021-09-13 at 12.14.37 PM957×831 61 KB

However, depending on the timeframe of the historical query, this point of interest disappears (it also disappears when the realtime mode is selected. Notice that the starting time has been set back by only 10 minutes:

Screen Shot 2021-09-13 at 12.17.27 PM
Screen Shot 2021-09-13 at 12.17.27 PM948×832 58.9 KB

I’m pretty sure this has to do with how the tag historian works behind the scenes, but this seems absurd to miss a point of interest (especially over such a small change in time range), and our users are unhappy about the ‘untrustworthiness’ of our charting. Is there something to be done on our end, or is this simply how it’s supposed to work?

Other potentially relevant information:

  • version 8.1.3
  • Float tag with On Change historical sample mode
  • Aggregation mode on the pen is LastValue, curveLinear interpolation, and breakLine is true

Thanks!

2 Likes
2

Bump. Users still unhappy. Still no idea what to do.

1 Like
3

Call support.

4

Fwiw [FEATURE] Increase usability of the Perspective Power Chart component

We’ve found the power chart very difficult to use effectively. For your issue, it’s due to sampling of the data instead of showing the raw data. It’s not possible at the moment to show raw data, you can only increase the samples taken which is super dodgy imo. Operators want to see exactly what happened, not roughly what happened for some values. For things like temperature, samples are fine, but for values that can change rapidly, it’s unusable

2 Likes