# Power Chart Y axis with fixed range (auto = False) still rescales to visible data (Ignition 8.3) **URL:** \ **Category:** Ignition\ **Tags:** perspective\ **Created:** [November 11, 2026, 11:28am UTC](https://forum.inductiveautomation.com/t/power-chart-y-axis-with-fixed-range-auto-false-still-rescales-to-visible-data-ignition-8-3/117810 "2026-11-11T11:28:08Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![desiroubos1](https://avatars.discourse-cdn.com/v4/letter/d/f6c823/32.png) [@desiroubos1](https://forum.inductiveautomation.com/u/desiroubos1)\ **Post date:** [November 11, 2026, 11:28am UTC](https://forum.inductiveautomation.com/t/power-chart-y-axis-with-fixed-range-auto-false-still-rescales-to-visible-data-ignition-8-3/117810/1 "2026-11-11T11:28:08Z")
The Power Chart is configured entirely from a script. For each pen, an axis with a fixed range is created. The low/high limits come either from a configuration table or from the tag’s EngLow/EngHigh properties. Before building, `props.axes` and `props.pens` are reset to `[]`. The pen’s axis is set to the same name as the axis. Take a trend with a fixed Y axis range of -1 to 10. When we open it on the last 24 hours, the axis shows -1 to 10 as expected, since the tag has been at -1 all day. But when the tag value is 9 and we switch the chart to realtime with a window of the last minute, so that only the value 9 is visible, the Y axis changes to roughly 8.9 to 10. If the visible window also contains lower values, for example 24 hours with both 0 and 9 in view, the axis stays at -1 to 10. So the fixed range only seems to be ignored when all the visible data is near the top of the range. I already tried converting min and max to `float`, hardcoding `'min': -1.0, 'max': 10.0`, and switching `interaction.mode` from `panAndZoom` to `xTrace`. None of these changed the behavior. The 8.3 documentation lists only `auto`, `min` and `max` under `axes[].range`, so i don't think a property is missing. Is this expected behavior or a bug? And is there a way to keep the Y axis truly fixed, regardless of the visible data? ---
**Author:** ![Samuel\_Sueur](https://avatars.discourse-cdn.com/v4/letter/s/e36b37/32.png) [@Samuel\_Sueur](https://forum.inductiveautomation.com/u/Samuel_Sueur)\ **Post date:** [November 11, 2026, 12:03pm UTC](https://forum.inductiveautomation.com/t/power-chart-y-axis-with-fixed-range-auto-false-still-rescales-to-visible-data-ignition-8-3/117810/2 "2026-11-11T12:03:23Z")
Hi, Are you sure the pen's axis is really set to the axis you want ? Just tested this out on 8.3.9 and it works if I configure it this way: ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/6/4/64f520438ef28c3d47ca80daaef10998ab82c54e.png) I tested this out with a sample tag that represents the number of seconds, and in realtime I'm watching the last 10 seconds. The chart does show me ONLY the range from 0 to 10. ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/2/3/239675559161346d6aeb6125e6dc936e4521a47a.png) **EDIT : Oh actually you might be right.** To be sure I was in the same conditions as you were, I put my `min` to -1 and it did start to behave completely differently.... Apparently it is truly a bug when your `min` is a negative value ? **EDIT 2:** Actually even weirder, if I put -2 as my `min`, it does work correctly again. Maybe a bug ONLY with` min = -1` ? ---
**Author:** ![desiroubos1](https://avatars.discourse-cdn.com/v4/letter/d/f6c823/32.png) [@desiroubos1](https://forum.inductiveautomation.com/u/desiroubos1)\ **Post date:** [November 11, 2026, 1:26pm UTC](https://forum.inductiveautomation.com/t/power-chart-y-axis-with-fixed-range-auto-false-still-rescales-to-visible-data-ignition-8-3/117810/3 "2026-11-11T13:26:33Z")
Thanks a lot for testing this, and for taking the time to reproduce it. That is very helpful. We can confirm the same: with a `min` of exactly -1 the axis starts rescaling to the visible data, while other values behave correctly. We changed our `min` from -1 to -1.1 as a workaround, and the axis now stays fixed and displays as -2 on the chart, so that works for us until this is fixed. ---
**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:** [November 11, 2026, 1:32pm UTC](https://forum.inductiveautomation.com/t/power-chart-y-axis-with-fixed-range-auto-false-still-rescales-to-visible-data-ignition-8-3/117810/4 "2026-11-11T13:32:16Z")
Please open a support ticket and report this bug. (This forum is not the official place to report bugs.)