If I want to create an analysis that generates an event frame in PI System Explorer, often times it's useful to check the values of variables to make sure that a calculation is being done as expected to mitigate error on my end, and make sure I am doing the calculation properly and have correct syntax for the order of operations (as an example). This can be done with expression types, which makes it easy to see the values of all the attributes and variables used in the analysis for a given time. There may also be a threshold that I may have to find by using the "guess and check" method, which is impossible with an event frame type. Ideally, the "Preview Results" window has a toggle switch that would still allow me to see event frames as they stand right now (start time, end time, name of event, etc), and I could just switch over to a preview results window that is similar to an expression type analysis.
