I am converting a system over to Ignition from IFIX. Most data comes in fine via OPC-UA, but on some devices I will get 80%+ good quality. Then I will just get random tags that show bad quality, the same tags work fine via OPC Client,IFIX, and other devices using same UDT. Anything worth looking into or any ideas what might be causing the issue?
If I had to guess without more information, your load factor on the PLC is probably to high. By what you stated your pulling the tags from 2 different SCADA systems at the same time and other devices are also using it. If both SCADA’s are pointing at the PLC, they are both going to be demanding part of the time that PLC has available to provide data. If it can’t send everything in its allotted time then some tags will show as good the ones that aren’t getting a response will show as bad quality.
The tags this happens to can change based on when the different systems call for updates. The PLC is going to process calls as they come in so it becomes a race between the different systems calling for data.
So far, we have broken out channels in Kepware, so IFIX and Ignition actually connect to the device on two separate channels. Seems to have cleaned up the data in testing so far, working to get it all converted over.