# Allen Bradley Firmware v20 and prior

**URL:** <https://forum.inductiveautomation.com/t/allen-bradley-firmware-v20-and-prior/6658>\
**Category:** Archived Topics\
**Created:** [June 6, 2013, 7:17pm UTC](https://forum.inductiveautomation.com/t/allen-bradley-firmware-v20-and-prior/6658 "2013-06-06T19:17:50Z")\
**Posts on this page:** 1\
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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:** [June 7, 2013, 12:09am UTC](https://forum.inductiveautomation.com/t/allen-bradley-firmware-v20-and-prior/6658/3 "2013-06-07T00:09:41Z")

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[quote=“Kevin.Herron”][quote=“everardohr”]  
Is there a protocol change in v21+ that is not supported by Ignition included drivers?  
[/quote]

Yes, that’s exactly right.  
[/quote]

Care to elaborate on the details of the protocol change? I do a great deal of low-level work with Ethernet/IP and I hadn’t noticed this.

(I did run into a protocol issue with recent A-B processors, but it affected all firmware versions on the newer processors.)

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