# Tag Historian - Rate issue **URL:** \ **Category:** Ignition Early Access\ **Tags:** perspective, ignition81\ **Created:** [January 18, 2023, 7:07pm UTC](https://forum.inductiveautomation.com/t/tag-historian-rate-issue/68748 "2023-01-18T19:07:24Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![luc.martin](https://avatars.discourse-cdn.com/v4/letter/l/77aa72/32.png) [@luc.martin](https://forum.inductiveautomation.com/u/luc.martin)\ **Post date:** [January 18, 2023, 7:07pm UTC](https://forum.inductiveautomation.com/t/tag-historian-rate-issue/68748/1 "2023-01-18T19:07:25Z")
I'm on 8.1.22 Not sure if I missed something, I try to set history on a tag with a sample rate of 1 minutes. I use Power chart to display the history and export data to csv file, in my file i see that tag value is insert every 2sec. I Also tried by used tag group and got same issue ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/9/7/978824fc77599a989c262d720bfca6aefa58ce4e.png) ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/0/2/0294e07cea879a0db4e96e1c5ca31f0ceaf89681.jpeg) ---
**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:** [January 18, 2023, 7:28pm UTC](https://forum.inductiveautomation.com/t/tag-historian-rate-issue/68748/2 "2023-01-18T19:28:48Z")
The observed rate from a query will not be the same as the actual sample rate unless you're using 'Natural' aggregation mode in your history query. What does your history query/binding/etc look like? ---
**Author:** ![luc.martin](https://avatars.discourse-cdn.com/v4/letter/l/77aa72/32.png) [@luc.martin](https://forum.inductiveautomation.com/u/luc.martin)\ **Post date:** [January 18, 2023, 7:40pm UTC](https://forum.inductiveautomation.com/t/tag-historian-rate-issue/68748/3 "2023-01-18T19:40:05Z")
> [@paul-griffith](#): > > mode in your history query ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/e/b/ebf85625ff17ece4b710cd60df9c6d28791e07f2.png) ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/1/2/12740211d77f0c71def98cb00b21a3a97492406a.png) ---
**Author:** ![luc.martin](https://avatars.discourse-cdn.com/v4/letter/l/77aa72/32.png) [@luc.martin](https://forum.inductiveautomation.com/u/luc.martin)\ **Post date:** [January 18, 2023, 7:47pm UTC](https://forum.inductiveautomation.com/t/tag-historian-rate-issue/68748/4 "2023-01-18T19:47:59Z")
I use PowerChart, it don't requier any binding to access data ---
**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:** [January 18, 2023, 9:23pm UTC](https://forum.inductiveautomation.com/t/tag-historian-rate-issue/68748/5 "2023-01-18T21:23:20Z")
Try setting the aggregate mode to `LastValue`? And/or try changing the point count property to -1. ---
**Author:** ![treyautomates](https://avatars.discourse-cdn.com/v4/letter/t/90db22/32.png) [@treyautomates](https://forum.inductiveautomation.com/u/treyautomates)\ **Post date:** [February 21, 2023, 7:46pm UTC](https://forum.inductiveautomation.com/t/tag-historian-rate-issue/68748/6 "2023-02-21T19:46:06Z")
Hoping to get a little clarity on this @paul-griffith. Csv export will export all data points used to create the power chart plot? Or will the export contain all DB entries during the time range? I guess we are confused as we are limiting power chart pointcount to 300 but getting 574 rows in the csv export. (Oddly in the export timestamps are duplicated every other row but have different data. There is a separate post already on that behavior so I only bring it up here in case it could be relevant). ---
**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 21, 2023, 8:34pm UTC](https://forum.inductiveautomation.com/t/tag-historian-rate-issue/68748/7 "2023-02-21T20:34:04Z")
> [@treyautomates](#): > > Oddly in the export timestamps are duplicated every other row but have different data That's normal for min/max aggregation. ---
**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 21, 2023, 9:12pm UTC](https://forum.inductiveautomation.com/t/tag-historian-rate-issue/68748/8 "2023-02-21T21:12:16Z")
The 'Export' functionality in the menu on the power chart only exports the data that's currently loaded in the chart. You can look at the network traffic yourself and confirm that no additional request is made from the frontend when you do an export. As Phil said - 'duplicate' entries with the same timestamp is expected for min/max aggregation, which is the default on the chart.