# U64 - Is 64bit read supported in Ignition 8.1?

**URL:** <https://forum.inductiveautomation.com/t/u64-is-64bit-read-supported-in-ignition-8-1/72408>\
**Category:** Ignition\
**Tags:** ignition81\
**Created:** [April 13, 2023, 2:15pm UTC](https://forum.inductiveautomation.com/t/u64-is-64bit-read-supported-in-ignition-8-1/72408 "2023-04-13T14:15:55Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Joe\_Lavalliere](https://avatars.discourse-cdn.com/v4/letter/j/c2a13f/32.png) [@Joe\_Lavalliere](https://forum.inductiveautomation.com/u/Joe_Lavalliere)\
**Post date:** [April 13, 2023, 2:15pm UTC](https://forum.inductiveautomation.com/t/u64-is-64bit-read-supported-in-ignition-8-1/72408/1 "2023-04-13T14:15:55Z")

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Hello, I am current trying to read in a U64, 4 consecutive holding registers, starting at 0xDF21 ~ 0xDFC0, where I need to do bitwise referencing afterwards. Is this the correct opcPath? Modbus ID = 255. I am wanting to read bit 0.

[U01B01\_BAMS]255.HRUS\_6457121.0

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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:** [April 13, 2023, 2:18pm UTC](https://forum.inductiveautomation.com/t/u64-is-64bit-read-supported-in-ignition-8-1/72408/2 "2023-04-13T14:18:14Z")

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It would be something ugly like `[U01B01_BAMS]255.HRI_6457121.0` or `[U01B01_BAMS]255.HRUI_6457121.0`. The prefix is `HRI_64` or `HRUI_64`.

[https://docs.inductiveautomation.com/display/DOC81/Modbus+Addressing](https://docs.inductiveautomation.com/display/DOC81/Modbus+Addressing)

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**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:** [April 13, 2023, 2:53pm UTC](https://forum.inductiveautomation.com/t/u64-is-64bit-read-supported-in-ignition-8-1/72408/3 "2023-04-13T14:53:50Z")

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> [@Joe\_Lavalliere](#):
>
> I am wanting to read bit 0.

Why do you need to read all four registers to get at one bit?

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<div class="post-metadata">

**Author:** ![Joe\_Lavalliere](https://avatars.discourse-cdn.com/v4/letter/j/c2a13f/32.png) [@Joe\_Lavalliere](https://forum.inductiveautomation.com/u/Joe_Lavalliere)\
**Post date:** [July 3, 2023, 5:00pm UTC](https://forum.inductiveautomation.com/t/u64-is-64bit-read-supported-in-ignition-8-1/72408/4 "2023-07-03T17:00:52Z")

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Great, thank you Kevin.. looks I just needed to substitute the HRU_S for HRU_I. Thank you very much!