I am using a 3rd party OPC server from OTTO Motors, whenever I write to a tag the quality goes from good to unknown and back to good. Any thoughts what I could look at to elimate ?
The scanclass is 1500ms, OPC data mode is read. I am only writing to a handfil of int4 tags at a time.
How are you writing to these tags?
using a tag event script in production, however I can replicate the issue by manually changing a value at the tag
When you write via scripting do you check the return values? Do the writes return bad quality?
What about writing from the Quick Client?
Writing a tag from the designer is roughly equivalent to a system.tag.writeBlocking, while writing from the QC is roughly equivalent to system.opc.writeValue. Might be interesting to see how they behave.
I should have added this is on 7.9.2
When you write via scripting do you check the return values? No
Do the writes return bad quality? I only notice the unknown quality in the tag browser.
What about writing from the Quick Client? I do not see the unknown quality.
The tag change event is with a Tag and uses: system.tag.writeSynchronous
I don’t know, maybe you can get a Wireshark capture of this happening?
I can’t really think of any reason this would happen on the Ignition side, my assumption right now is that the server temporarily reads an uncertain/bad quality after you write for some reason.