I have a PI tag (call it "Tag A") that I wrote a custom value to from Excel using VBA. I have another PI tag that is taking data from the plant (call it "Tag B"). I want to use PI Calculation Data on PI ProcessBook to create the following expression: 'Tag B'/'Tag A'.
When I do this, I immediately get the following error: "Error Evaluating Tag or Expression". Is there something that I am doing wrong?
Maybe because Tag A is a manually inputted number, it is not able to be put into a formula. If that is the case, is there another way that I can achieve my calculation and be able to make a "value" trend on PI? For reference, I have +170 manually written PI tags from another data source (Excel) that I want to do this calculation with.