# Realtime Power Chart Historian Needed?

**URL:** <https://forum.inductiveautomation.com/t/realtime-power-chart-historian-needed/43751>\
**Category:** Ignition\
**Created:** [February 23, 2021, 8:43pm UTC](https://forum.inductiveautomation.com/t/realtime-power-chart-historian-needed/43751 "2021-02-23T20:43:04Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![jramirez3](https://avatars.discourse-cdn.com/v4/letter/j/a183cd/32.png) [@jramirez3](https://forum.inductiveautomation.com/u/jramirez3)\
**Post date:** [February 23, 2021, 8:43pm UTC](https://forum.inductiveautomation.com/t/realtime-power-chart-historian-needed/43751/1 "2021-02-23T20:43:04Z")

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For the power chart, do you have to have history configured on the chart? Or can it plot from the point in time you loaded the screen/view?

So if you specifiy the last 10 seconds, it will start overriding itself after 10 seconds worth data.

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**Author:** ![paul-griffith](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/paul-griffith/32/37249_2.png) [@paul-griffith](https://forum.inductiveautomation.com/u/paul-griffith)\
**Post date:** [February 23, 2021, 9:26pm UTC](https://forum.inductiveautomation.com/t/realtime-power-chart-historian-needed/43751/2 "2021-02-23T21:26:57Z")

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You must have the historian. Ignition doesn’t have any builtin ability to do a ‘local’ value trend. There are some third-party modules/efforts to do so in Vision, I believe, but I don’t think anyone’s done so in Perspective (yet?).

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**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\
**Post date:** [February 24, 2021, 2:17am UTC](https://forum.inductiveautomation.com/t/realtime-power-chart-historian-needed/43751/3 "2021-02-24T02:17:19Z")

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My [recorder()](https://www.automation-pros.com/simaids/doc/expression.recorder.html) expression function (from [Simulation Aids](https://inductiveautomation.com/moduleshowcase/module/automation-professionals-llc-simulation-aids)–free!) should work in Perspective.