# Interesting difference between 7.x and 8.x Tag Mapping

**URL:** <https://forum.inductiveautomation.com/t/interesting-difference-between-7-x-and-8-x-tag-mapping/101112>\
**Category:** Module Development\
**Created:** [January 20, 2025, 3:32pm UTC](https://forum.inductiveautomation.com/t/interesting-difference-between-7-x-and-8-x-tag-mapping/101112 "2025-01-20T15:32:02Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![BillS](https://avatars.discourse-cdn.com/v4/letter/b/9fc348/32.png) [@BillS](https://forum.inductiveautomation.com/u/BillS)\
**Post date:** [January 20, 2025, 3:32pm UTC](https://forum.inductiveautomation.com/t/interesting-difference-between-7-x-and-8-x-tag-mapping/101112/1 "2025-01-20T15:32:02Z")

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Hello,

Not really sure if this falls within Module Development or is more general purpose.

I ran across an interesting difference in behavior between the driver I'm porting between when it used the XOPC transition module and when I switched it over to the newer interface.

If your tag definitions in the designer do not contain the ns=1;s= portion of the definition, then the tag bounces between a "GOOD" status and an error indicating that the tag couldn't be found in the OPC-UA gateway. I didn't copy the exact error message, it flashed up fairly quickly. Once I added in the above, the tag started working correctly, as far as reading goes anyways.

I did not see this behavior with the older style even on 8.x.

Yes, I realize that the above is the recommended/required way of defining the OPC-UA item path to the tag definitions, this project was the first I did with Ignition and it didn't seem to matter, so none of the definitions in the UDT's that I set up had it in.

Anyways, this is just an informative message, nothing to do here.

Bill S.