# OPC UA driver defenitions?

**URL:** <https://forum.inductiveautomation.com/t/opc-ua-driver-defenitions/9454>\
**Category:** Ignition\
**Created:** [December 16, 2014, 4:55pm UTC](https://forum.inductiveautomation.com/t/opc-ua-driver-defenitions/9454 "2014-12-16T16:55:22Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![AutomatedDeere](https://avatars.discourse-cdn.com/v4/letter/a/f05b48/32.png) [@AutomatedDeere](https://forum.inductiveautomation.com/u/AutomatedDeere)\
**Post date:** [December 16, 2014, 4:55pm UTC](https://forum.inductiveautomation.com/t/opc-ua-driver-defenitions/9454/1 "2014-12-16T16:55:22Z")

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Hello all;

we are currently tracing back an issue were L7X controllers expirence fault code 62…meaning a Major Non-Recoverable Fault and completed erased the PLC. in researching tag writing types (DMA or Symbolic instance - tag name), we’ve found with newer controllers you want symbolic because the memory in newer controllers is free-form. meaning one moment it may be set for a tag, the next its memory for a rung.

my question is can someone define the differences between opc-ua driver 2.7.0 and 2.7.1 rc3. more specifically relating to what i stated above.

any help is greatly appreciated.

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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:** [December 16, 2014, 5:29pm UTC](https://forum.inductiveautomation.com/t/opc-ua-driver-defenitions/9454/2 "2014-12-16T17:29:08Z")

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Are you using the new Logix v21+ driver that was released with 7.7 or the legacy ControlLogix/CompactLogix driver?

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**Author:** ![AutomatedDeere](https://avatars.discourse-cdn.com/v4/letter/a/f05b48/32.png) [@AutomatedDeere](https://forum.inductiveautomation.com/u/AutomatedDeere)\
**Post date:** [December 16, 2014, 5:42pm UTC](https://forum.inductiveautomation.com/t/opc-ua-driver-defenitions/9454/3 "2014-12-16T17:42:35Z")

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well we have 2 sites using ignition, with one site using 2 servers, not in redundancy.

site one is running ignigtion 7.7.1 rc3, opc-ua driver 7.7.1 rc3

site two, server one is running ignition 7.7.0, opc-ua driver 2.7.0  
site two, server two is running ignition 7.7.0, opc-ua driver 2.7.0

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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:** [December 16, 2014, 5:49pm UTC](https://forum.inductiveautomation.com/t/opc-ua-driver-defenitions/9454/4 "2014-12-16T17:49:58Z")

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Next to the device entry in the gateway does it say “Allen-Bradley ControlLogix” or “Allen-Bradley Logix Driver”? The former means you’re using the legacy driver for v20 and prior controllers, the latter means you’re using the new v21+ driver.

The v21+ driver uses symbolic or instance id addressing when doing reads and writes; it does not use memory location based addressing. This is no longer possible in firmware v21 and newer and is the reason a new driver had to be developed in the first place.

I’ll have to check if the older driver uses memory location addressing for writes - I suspect it does, but this is allowed in v20 and prior firmware versions.

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**Author:** ![AutomatedDeere](https://avatars.discourse-cdn.com/v4/letter/a/f05b48/32.png) [@AutomatedDeere](https://forum.inductiveautomation.com/u/AutomatedDeere)\
**Post date:** [December 16, 2014, 6:09pm UTC](https://forum.inductiveautomation.com/t/opc-ua-driver-defenitions/9454/5 "2014-12-16T18:09:13Z")

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it looks to be on all 3 servers that we are using the legacy driver. can you please research the addressing for writing for this driver?

thank you so much for the quick responses and support.

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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:** [December 16, 2014, 6:58pm UTC](https://forum.inductiveautomation.com/t/opc-ua-driver-defenitions/9454/6 "2014-12-16T18:58:54Z")

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I confirmed with the developer of the older driver, it does not use memory location based addressing when doing writes.

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**Author:** ![AutomatedDeere](https://avatars.discourse-cdn.com/v4/letter/a/f05b48/32.png) [@AutomatedDeere](https://forum.inductiveautomation.com/u/AutomatedDeere)\
**Post date:** [December 16, 2014, 8:16pm UTC](https://forum.inductiveautomation.com/t/opc-ua-driver-defenitions/9454/7 "2014-12-16T20:16:40Z")

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Thank you very much for the quick responses.

That’s what I needed clarification on.

Thanks again.