We have nearly 80 PLC;s connected via modbus tcp and after we upgraded to 7.8 we have found the tags will go stale sometimes and quality of tag shows “Uncertain”. values show up still instead of showing null but the tags are either redx or green config error. If we highlight the tags in a project and reapply the scan class they show good again until the next time they decide to go stale. Why is this happening after 7.8 upgrade? Is their some sort of timing or disconnect affecting this? It’s becoming an issue to have to restart gateway or reapply scan classes to get the tags reading again.
We’re working through some OPC-UA issues; if you contact support they can give you the latest beta version of the module. It should get you fixed up.
Just got off the phone with Support actually…sending me the new module. Ill install it and see how it works out.
Any update on this? I’m keenly interested in this topic.
I have the same issue with tags going Logix5000 tags going stale periodically after the 7.8 upgrade, please advise as to what module needs to be updated to which version…
The 7.8.1-beta1 build available in the downloads section has all fixes that were made.
Periodically stale tags might be a different issue than what’s being talked about here, though. If they recover on their own it might just be that you’re not achieving enough throughput for the amount of tags you’re reading or the speed you’re trying to read them at.
I was having this issued, installing the OPC-UA module from 7.8.2 Beta2 fixed it for me.