# How to scale Analog Input values - Siemens PLC

**URL:** <https://forumautomation.com/t/how-to-scale-analog-input-values-siemens-plc/207>\
**Category:** Siemens\
**Created:** [December 27, 2014, 2:44am UTC](https://forumautomation.com/t/how-to-scale-analog-input-values-siemens-plc/207 "2014-12-27T02:44:44Z")\
**Posts on this page:** 1\
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**Author:** ![denizen](https://forumautomation.com/letter_avatar_proxy/v4/letter/d/848f3c/32.png) [@denizen](https://forumautomation.com/u/denizen)\
**Post date:** [December 27, 2014, 2:44am UTC](https://forumautomation.com/t/how-to-scale-analog-input-values-siemens-plc/207/1 "2014-12-27T02:44:45Z")

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**Siemens PLC Analog Input Scaling** The following variables are pertinent to the scaling formula: Ov = scaled output value Iv = analog input value Osh = high limit of the scale for the scaled output value Osl = low limit of the scale for the scaled output value Ish = high limit of the scale for the analog input value Isl = low limit of the scale for the analog input value

The scaling scheme can be diagrammed as follows: The following formula for calculating the scaled value can be derived from the diagram: Ov = [(Osh – Osl) \* (Iv -Isl) / (Ish – Isl)] + Osl Which can be rewritten as: Ov = [(Osh -Osl)/(lsh-lsl)/(lsh -lsl)] + Osl