# Assistance with PLC Tag Display Adjustments and tag histogram

**URL:** <https://forum.inductiveautomation.com/t/assistance-with-plc-tag-display-adjustments-and-tag-histogram/92279>\
**Category:** Ignition\
**Tags:** database, ignition81\
**Created:** [June 24, 2024, 1:17pm UTC](https://forum.inductiveautomation.com/t/assistance-with-plc-tag-display-adjustments-and-tag-histogram/92279 "2024-06-24T13:17:46Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Rajashekar\_Reddy](https://avatars.discourse-cdn.com/v4/letter/r/c0e974/32.png) [@Rajashekar\_Reddy](https://forum.inductiveautomation.com/u/Rajashekar_Reddy)\
**Post date:** [June 24, 2024, 1:17pm UTC](https://forum.inductiveautomation.com/t/assistance-with-plc-tag-display-adjustments-and-tag-histogram/92279/1 "2024-06-24T13:17:46Z")

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Hi.

I am reaching out to seek assistance with the Perspective module. I need to display a tag that incorporates mathematical calculations to adjust the raw value obtained from a PLC.

For instance, the raw value displayed by PLC tag-1 is 1526. I would like to apply an offset or a conversion factor to this value, such as adding 10.52 or dividing by 0.01, before it is displayed on the screen. The objective is to present a modified value that reflects necessary adjustments for accurate monitoring and analysis.

Furthermore, it is crucial for our tag histogram data to log these adjusted values instead of the raw data from the PLC. This will ensure that our historical records are consistent with the displayed information and can be used reliably for trend analysis and reporting purposes.

I would greatly appreciate your guidance on how to configure the system to meet these requirements. Your expertise in this matter is invaluable to us.

Thank you for your attention to this request.

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**Author:** ![Transistor](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/transistor/32/3380_2.png) [@Transistor](https://forum.inductiveautomation.com/u/Transistor)\
**Post date:** [June 24, 2024, 1:38pm UTC](https://forum.inductiveautomation.com/t/assistance-with-plc-tag-display-adjustments-and-tag-histogram/92279/2 "2024-06-24T13:38:55Z")

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That's what the tag scale mode is for!

 ![Tag scaling](https://us1.discourse-cdn.com/inductiveautomation/original/3X/8/c/8ce34fdb36e6d4cc471b8ad14a762953a28139d7.png)

You should be saving engineering measurements to your database - not raw counts.

> **[Tag Properties | Ignition User Manual](https://docs.inductiveautomation.com/docs/8.1/platform/tags/tag-properties#numeric-properties)**
>
> Tags are points of data and may have static values or dynamic values that come from an OPC address, an Expression, or a SQL query. The values can be used on screens and in Transaction Groups. Additionally, tags offer a core set of features above and...

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<div class="post-metadata">

**Author:** ![lrose](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/lrose/32/62724_2.png) [@lrose](https://forum.inductiveautomation.com/u/lrose)\
**Post date:** [June 24, 2024, 1:40pm UTC](https://forum.inductiveautomation.com/t/assistance-with-plc-tag-display-adjustments-and-tag-histogram/92279/3 "2024-06-24T13:40:54Z")

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I don't think that this is really specific to perspective.

There are several ways this can be achieved.

1. Use scaling on the tag.
  - Note: Scaling works both directions  
[Tag Scaling Properties | Ignition User Manual](https://docs.inductiveautomation.com/docs/8.1/platform/tags/tag-properties/tag-scaling-properties)

2. Use a derived tag, and historize the derived tag.
  - [Types of Tags | Ignition User Manual](https://docs.inductiveautomation.com/docs/8.1/platform/tags/types-of-tags#reference-and-derived-tags)

3. Use an expression tag
  - [Types of Tags | Ignition User Manual](https://docs.inductiveautomation.com/docs/8.1/platform/tags/types-of-tags#expression-tags)

You can also use tag change scripts and a memory tag, but I would avoid that the other options are much better. Notice that none of these options have anything to do with either UI module?