I had this problem last week and had not had the chance to post it. I worked out a fix, but now my client has had a power outage and the problem is back. I have several tags that are reporting bad quality. It only seems to happen with tags that were added with the OPC browse and have also been addressed with a user defined data type. As a bit of background, I am slowly updating an existing project with user defined data types and until I have completed my screen ties to the new tag structures, I have several tags that address the same location in the PLC as existing tags in the tag list. Some of those tags started showing bad quality, but not all. While trying to figure out where the problem was, I copied yet another set of tags into a new folder from the OPC browser. Not only did those tags come into the project working normally, but the process of copying those tags fixed all others in the project. I was able to delete the tags copied over to fix everything and still maintain good data quality on all of the previously existing tags. Now with the recent power outage, some or all of the problem tags are reporting bad quality. I have created a separate folder to copy all of the problem tags via the OPC browser and that is solving the problem temporarily; however, there will need to be a fix for this.
I need to add that this is using the ControlLogix OPCUA driver and that the tags in the Logix are also user defined data types. The problem tags involve a UDT for valves and a UDT for motors. It is a mixture of BOOLs and DINT’s for screen pushbuttons and status.
Hopefully this is understandable as I am trying to fit this in as I fix this issue for my client’s startup tomorrow.