What is it that allows ignition to view live tag values in the tag browser while having Designer open?
Yes, Thank you.
I was curious about what underlying mechanism/programming makes it possible to have live tag values displayed in the Tag Browser shown in your screen shot. I figured it is apart of the OP UA server, but was not sure for example if I have a device reading battery voltage and can see it constantly updating down to one one-hundredth of a volt seemly not to skip any change.
OPC is one of the mechanisms that might be updating a tag, but this all happens on the Gateway.
Between the Designer and Gateway is an HTTP connection that is polling for updates using our own implementation. In 8.3 that becomes a WebSocket connection, but this is really just an implementation detail for most people.