# Modbus Input register - Uncertain\_InitialValue

**URL:** <https://forum.inductiveautomation.com/t/modbus-input-register-uncertain-initialvalue/57360>\
**Category:** Ignition\
**Created:** [March 18, 2022, 12:56pm UTC](https://forum.inductiveautomation.com/t/modbus-input-register-uncertain-initialvalue/57360 "2022-03-18T12:56:53Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![William\_Oliver\_Foste](https://avatars.discourse-cdn.com/v4/letter/w/8c91f0/32.png) [@William\_Oliver\_Foste](https://forum.inductiveautomation.com/u/William_Oliver_Foste)\
**Post date:** [March 18, 2022, 12:56pm UTC](https://forum.inductiveautomation.com/t/modbus-input-register-uncertain-initialvalue/57360/1 "2022-03-18T12:56:53Z")

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I have an issue reading modbus input register on a inverter configured ass follow:

 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/a/7/a75749850cb9236276778f6b980c6ae6be66dbac.png)

![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/5/f/5f917905b3068144ecb35cb416e53a5789333c9e.png)

The OPC Item path i tried is:  
ns=1;s=[INV13]IR1

I also tried

[INV13]IR1

However radzio and modbuspoll read correctly

![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/a/5/a5d692519cba0ce0eae9a813b4bc23ce5598031c.png)

I think there an issue on the configuration i would apreciate any suggenstion.

Best

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<div class="post-metadata">

**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\
**Post date:** [March 18, 2022, 1:05pm UTC](https://forum.inductiveautomation.com/t/modbus-input-register-uncertain-initialvalue/57360/2 "2022-03-18T13:05:56Z")

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Try `1.IR1` as your address.