# Modbus Tag Adressing for Longs and Shorts

**URL:** <https://forum.inductiveautomation.com/t/modbus-tag-adressing-for-longs-and-shorts/52678>\
**Category:** Ignition\
**Created:** [November 3, 2021, 2:45pm UTC](https://forum.inductiveautomation.com/t/modbus-tag-adressing-for-longs-and-shorts/52678 "2021-11-03T14:45:54Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![ftuquabo](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/ftuquabo/32/29161_2.png) [@ftuquabo](https://forum.inductiveautomation.com/u/ftuquabo)\
**Post date:** [November 3, 2021, 2:45pm UTC](https://forum.inductiveautomation.com/t/modbus-tag-adressing-for-longs-and-shorts/52678/1 "2021-11-03T14:45:54Z")

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How should I address long and short Modbus addresses in ignition for OPC Tags?

Modbus Address Examples: 400467 L  
400470 S  
400469 S  
400461 L  
400463 L

So for 400467L, would the address be [DEVICENAME]HRL467?

For 400470, would the address be [DEVICENAME]HRS470?

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**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:** [November 3, 2021, 3:13pm UTC](https://forum.inductiveautomation.com/t/modbus-tag-adressing-for-longs-and-shorts/52678/2 "2021-11-03T15:13:48Z")

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Shorts are 16-bit, so just `[Device]HR470` etc…  
Longs are 64-bit, so `[Device]HRI_64461` etc… (yes, the syntax is ugly because the “64” runs into the address)

The address syntax is documented here: [Modbus Addressing - Ignition User Manual 8.1 - Ignition Documentation](https://docs.inductiveautomation.com/display/DOC81/Modbus+Addressing)

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<div class="post-metadata">

**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 3, 2021, 7:45pm UTC](https://forum.inductiveautomation.com/t/modbus-tag-adressing-for-longs-and-shorts/52678/3 "2021-11-03T19:45:58Z")

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> [@Kevin.Herron](#):
>
> the syntax is ugly because the “64” runs into the address

I implemented the prettier "HRL" syntax (and HRUL) in my [Advanced Modbus Driver](https://inductiveautomation.com/moduleshowcase/module/automation-professionals-llc-advanced-modbus).... (: