Hi, everyone.
I have a power chart and I want to bind a historical tag path to pen[0].data.source property of the power chart for displaying the tag value. However, when I made a binding with a view’s param, it automatically added tag provider “[default]” into my tag path. Therefore, the system didn’t recognize the historical tag.
You can see this in the figure below.
As you can see when I use expression tag binding, it added tag provider “[default]” into tag path. I guest that is the reason for the “Bad_NotFound” error. Because when I used property and expression bindings instead of tag expression binding, it worked. The tag path didn’t contain the tag provider “[default]”.
The power chart is heavily integrated with Ignitions Tag Historian. You should be using the tag browser to select tags. If you don’t want to use the tag browser you are probably better off using the time series chart or the XY chart.
What happens when a user removes your pen with the binding on it?
As for the bindings:
A tag binding in expression mode is expecting the resultant value to resolve to a non-historical tag path, if there is no provider in the path, then it adds the projects default provider, in your case that is [default].
The expression “works” because it doesn’t have any restrictions on what the expression should resolve to. So it evaluates the expression since the Pen Source is expecting a historical tag path, it works.
