# Power Chart missing "important" values?

**URL:** <https://forum.inductiveautomation.com/t/power-chart-missing-important-values/50911>\
**Category:** Ignition\
**Tags:** ignition81, perspective\
**Created:** [September 13, 2021, 5:28pm UTC](https://forum.inductiveautomation.com/t/power-chart-missing-important-values/50911 "2021-09-13T17:28:20Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![kirsten.chambers](https://avatars.discourse-cdn.com/v4/letter/k/48db29/32.png) [@kirsten.chambers](https://forum.inductiveautomation.com/u/kirsten.chambers)\
**Post date:** [September 13, 2021, 5:28pm UTC](https://forum.inductiveautomation.com/t/power-chart-missing-important-values/50911/1 "2021-09-13T17:28:20Z")

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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](https://us1.discourse-cdn.com/inductiveautomation/original/3X/a/a/aa3db08c0e58063e169f266d38c717588d832fdf.jpeg)

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](https://us1.discourse-cdn.com/inductiveautomation/original/3X/7/a/7a7284cf9ccbb45ac6c7d1fecda496e8f2631db0.jpeg)

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!

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<div class="post-metadata">

**Author:** ![kirsten.chambers](https://avatars.discourse-cdn.com/v4/letter/k/48db29/32.png) [@kirsten.chambers](https://forum.inductiveautomation.com/u/kirsten.chambers)\
**Post date:** [October 21, 2021, 7:47pm UTC](https://forum.inductiveautomation.com/t/power-chart-missing-important-values/50911/2 "2021-10-21T19:47:22Z")

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

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**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\
**Post date:** [October 21, 2021, 7:53pm UTC](https://forum.inductiveautomation.com/t/power-chart-missing-important-values/50911/3 "2021-10-21T19:53:16Z")

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> [@kirsten.chambers](#):
>
> Still no idea what to do.

Call support.

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**Author:** ![nminchin](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/nminchin/32/6911_2.png) [@nminchin](https://forum.inductiveautomation.com/u/nminchin)\
**Post date:** [October 21, 2021, 8:03pm UTC](https://forum.inductiveautomation.com/t/power-chart-missing-important-values/50911/4 "2021-10-21T20:03:57Z")

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Fwiw [[FEATURE] Increase usability of the Perspective Power Chart component](https://forum.inductiveautomation.com/t/feature-increase-usability-of-the-perspective-power-chart-component/51474)

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