How to Add PI Points to an XY-Plot in PI ProcessBook from .NET Code

Integrating PI Points into XY-Plots in PI ProcessBook Using .NET and AF SDK

One common task for engineers and developers working with OSIsoft PI ProcessBook is dynamically adding PI Points or AF Attributes to an existing XY-Plot. Traditionally, this operation is straightforward in ProcessBook VBA, but what if you’re developing a PI ProcessBook add-in using .NET (VB or C#) and the AF SDK? Let’s walk through how this can be accomplished.

The Challenge

Suppose you want to perform, from .NET VB code, what you could perform in VBA:

Dim aDefinition As XYDefinition
Set aDefinition = ThisDisplay.SelectedSymbols.Item(1).GetDefinition
aDefinition.Tags.Add(sTagName)
ThisDisplay.SelectedSymbols.Item(1).SetDefinition aDefinition
Set aDefinition = Nothing

How do you achieve this in .NET with ProcessBook add-in templates?

Understanding the Approach

Although AF SDK is powerful for managing PI Systems and Asset Framework data structures, the ProcessBook display manipulation (adding tags to an XY Plot, for example) is still governed by the libraries and COM interfaces provided by ProcessBook itself. Therefore, the approach is:

1. Reference the XYPlot .NET Library: This provides you with the .NET objects needed to interact with and modify XY Plots within your ProcessBook add-in.
2. Access the Display and Selected Symbol: From .NET code, obtain the active display and the selected XY-Plot symbol.
3. Modify the XYDefinition: Get the symbol’s definition, add your desired PI Point or AF Attribute (the same way as in VBA), and set the modified definition back.

Practical Implementation Steps

Let’s say you’re using the OSIsoft PI ProcessBook add-in .NET VB template. Here’s how to add a PI Point (or AF Attribute) to an XY-Plot:

1. Add the XYPlot .NET Library

Reference XYPlotLib.dll (or the equivalent library shipped with ProcessBook) in your .NET project. This exposes the needed classes and interfaces.

2. Use the Familiar Methodology

Your code in .NET VB will look remarkably similar to VBA:

Imports PBObjLib
Imports XYPlotLib

' Inside your add-in code
Dim display As Display = application.ActiveDisplay
Dim xySymbol As Symbol = display.SelectedSymbols.Item(1)
Dim xyDef As XYPlotDefinition = xySymbol.GetDefinition()

' Add the tag or attribute
xyDef.Tags.Add(sTagName)

' Apply the modified definition
xySymbol.SetDefinition(xyDef)

You may need to cast or convert the symbol and definition types based on your application structure.

3. Notes

• Ensure you handle object releases and COM references properly to avoid locking symbols or causing memory leaks.
• Error checking (e.g., verifying SelectedSymbols count, type checking the symbol) is important for robust add-ins.
• You can add both PI Tag names and AF Attribute paths as needed.

Conclusion

By referencing the XYPlot .NET library, you can manipulate XY-Plots within PI ProcessBook from a .NET add-in using virtually the same logic as VBA. This approach allows you to build robust, user-friendly ProcessBook extensions that dynamically modify plots based on user input or automated criteria.

If you have old VBA logic you want to port, this interoperability with .NET makes it possible without major rewrites—streamlining your transition to modern add-in development.