In PI System Explorer I would like to know the proper syntax for using substitution parameters in Analysis Templates. This is an example of the hard coded 'TagAvg' expression:
|PITagAverage||TagAvg('Attribute_Name', 'y', 't')|
I want to substitute the 'y' and the 't' for string attributes located in a parent and/or grandparent element. I have tried dozens of substitution parameters found in the PI System Explorer User Guide to no avail. I have tried putting them in parentheses inside the single quotes, etc., etc.
I have tried sibling attributes too. My last attempt doing this, in addition to the 'Calc Failed', ended with this error message:
PITagAverage: Invalid start time: y. It must be time or time span.
Parameter name: 'startTime'
The last time I checked the value of 'y' was a suitable start time in PI system expressions. So what am I missing? Is there a resource about Analysis Templates substitution parameters I can turn to for guidance? I am especially interested in hearing from anyone who encountered this and solved it.
I appreciate your feedback.