Periodically when adding new tags or restarting existing tags, quality shows as Uncertain_InitialValue

Since upgrading from 7 to v8.1.0 onsite, we’ve periodically been seeing that when we add new tags, edit existing, or restart existing tags from the context menu, their values won’t come in and their qualities remain Uncertain_InitialValue.

The only resolution that I’ve found it to completely restart the gateway. I have tried restarting the tag provider itself, however from memory this just meant that all tags had this quality.

The last time this happened was about 2 weeks ago, and now it’s just happened again. The site is operational basically 24/7 so rebooting SCADA is not great! I’ll contact support tomorrow morning (Aus time), but in the meantime, does anyone have any suggestions?

Edit: note that this only affects tags coming from devices e.g. Allen-Bradley PLCs. Internal Ignition memory tags are unaffected…

8.1.2 is the current stable, any reasons you’re not availing of that release?

We upgraded to 8.1.0 a few months ago, from memory we’ve only seen it happen 3 times now but we’re planning to upgrade to 8.1.3 as we’ve been holding out for the fix to the Perspective on-screen keyboard when running Perspective in Vision in the web browser component

Are the AB PLCs version 32?

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Not all of them but some. Will need to check if its happening to all devices. Is there an issue with 32?


If when these tags are stuck in Uncertain the Logix devices they belong to are in a perpetual Idle state then it’s a known issue.

Coincidentally, I think we just tracked it down and I’m going to be resurrecting one of the old threads about it to upload a module for testing.

If it’s not the Idle thing and instead you see errors in the logs when browsing/re-browsing then it’s a v32 firmware bug that has to be remedied by a program download or (reportedly) upgrading to v33.

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@Kevin.Herron I’ve just checked and the issue is affecting a lot of drivers, not just Logix. Any tag I drag in from the OPC browser or create manually is in this state, including the diagnostic OPC tags part of devices.

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Upgrade and/or call support :man_shrugging: