seneschal

Viewing tag values during Event Frame duration

Discussion created by seneschal on Jul 18, 2014
Latest reply on Jul 22, 2014 by seneschal

There appears to be an issue with the PI System Explorer and the way it displays the values within the time range of the event frame. It has to do with the "Inside" and "Outside" boundary type. Let me show you some screenshots.

 

I have created a PI tag, an Attribute for the PI tag, a bunch of values for the PI tag over a time range, and an event frame that has the same time range. The FIRST tag value is at StartTime, and the LAST tag value is at EndTime. The attribute is linked to the event frame.  

 

Let's focus on looking at the LAST PI tag value.

 

In PI System Explorer, when I look at the attribute from the Elements view (Attributes tab) I see the most recent value, 0.2123999, which is the correct last value:

 

2313.1.jpg

 

When I navigate to the same attribute from the event frame view, it is not showing the latest value (0.2123999) because the latest value is PRECISELY at the end time of the event frame. It shows 0.234033227 - which by the way seems extrapolated between the last 2 values, because its not the previous value!

 

 3817.2.jpg

 

I have seen that by doing a time series (right-click the attribute, choose "Time Series"). The "Boundary Type" by default is "Inside". Again I see the same value 0.234033227. But when I change the Boundary type to "Outside" I finally see the right value 0.2123999.

 

6888.3.jpg

 

My customer came up with the question of why are these two views showing different “most recent” values when they should be the same? I tend to agree. They think it is a problem with our software.

 

I am not sure if there was something I could do during creation of the event frame to prevent this Inside/Outside issue, or if that’s just the way things work in PI System Explorer?

 

I had the thought of making the end time 1 ms longer, but I would rather not because the start and end time of the event frame correspond to something else specific to our application.

 

Thanks,

 

Dave

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