PI ProcessBook 3.2 Includes Both Module Relative and Element Relative Display Features

Blog Post created by ldieffenbach on Sep 16, 2009

PI ProcessBook 3.2 represents a transitional version of display relativity, where you can build one display and choose the equipment of interest dynamically. New tools for automating the migration of Module Database content to AF are in progress, but have not been released yet. As you consider migrating from existing Module Database-based ProcessBook displays to AF-based ProcessBook displays, note that both the existing Module Relative Display (MRD) add-in as well as the new Element Relative Display (ERD) add-in are provided with version 3.2 of PI ProcessBook. Because both add-ins are installed by default, you may have some questions about how and when to use each add-in. This article is intended to address those anticipated questions.

Use MRD if…

If you have not migrated your existing Module Database to AF, if you have existing displays that you continue to use that were built with the MRD provided with earlier versions of PI ProcessBook, if you use BatchView and want to create new displays with relativity, if you use the DataSheet Control, or if you use IT Overview, then you should use the MRD add-in to select a module of interest for the display or to create or edit new displays.
Note that there are some limitations to creating new MRD displays. If a Module database has been migrated to an AF database, then a new display no longer lists this Module database when selecting Available Modules for a new MRD display. There are no limitations for updating existing MRD displays.

Use ERD if…

If you do not have an existing Module Database or have already migrated it to AF, and have started to use and configure AF, you should (1) remove the MRD add-in using the Add/Remove Programs entry and (2) use the ERD add-in to create, edit and use displays that are element relative (different data appears when a different element is selected from the Elements of Interest list).
Note that the MRD add-in is installed with a separate MSI, so automated software deployment systems can be used to automatically remove it. In addition, the setup.ini file shipped with PI ProcessBook 3.2 specifies that the MRD.msi is included in the installation. If you use automated software deployment systems, you can customize the setup.ini or silent.ini to remove this item from the installation.


Migrating an existing Module Database to AF can be accomplished once the PI Server 3.5 EAM release is available (projected for 2010). This release schedule has an impact on how to decide whether to use the MRD add-in or the ERD add-in. When the Module Database to AF migration tools are released, there will be additional information about how best to implement them.
If you have both existing MRD displays and an AF database you want to use, you should use the MRD add-in to navigate existing MRD displays and you should use the ERD add-in to create new displays. Once you have migrated your Module database using the Asset subsystem in PI Server 3.5, you should (1) remove the MRD add-in using the Add/Remove Programs entry and (2) use the ERD add-in to upgrade the existing MRD displays to use their AF equivalents.


After you migrate a Module Database to AF, that Module Database tree is no longer visible in the user interface for selecting modules in the MRD add-in for new displays as described above. Existing MRD displays continue to work, but there is no user interface to build new ones. For most customers, this is not an issue, since you can remove the MRD add-in, automatically upgrade the existing displays to use ERD and continue building new displays with that way.

Limitations on migrating your Module Database to an AF database

If you use BatchView or the Datasheet Control or the IT Overview add-in for PI ProcessBook, there is an existing dependency on the MRD add-in for creating symbols with relativity that will be addressed in a later PI ProcessBook release. For those customers, migrating the module database to AF will have limitations until the updated BatchView, IT Overview and Datasheet Control functionality is in place. Until then, use the earlier version of PI ProcessBook (3.1) to create new MRD displays once the Module database is migrated. If the module database isn’t migrated, you can continue using the MRD as before.

Migration Validation

You may want to use the existence of the MRD and ERD add-ins to check the status of and verify your Module Database to AF migration (once that is available in PI Server 3.5). This is best accomplished by comparing two displays: one created with the MRD and one created with the ERD, looking at the same assets.

Important Note

Combining ERD and MDB references on the same display is NOT supported, even though there is no mechanism to prevent this. If a display contains both ERD and MRD references and the MRD add-in is removed from the computer, the ERD add-in attempts to convert the MRD references, with potential consequences for the existing ERD references. We strongly advise customers not to combine references on a single display. The PI ProcessBook 3.2 Release Notes explain that this is an unsupported feature.

VBA Implications

Many users have VBA code in displays behind buttons that change the context. An example of this would be code like:


Sub SwitchContexts()
     Dim mrd as ContextHandler


     Set mrd = ThisDisplay.Application.ContextHandlers.Item("Alias")


     mrd.CurrentContext(ThisDisplay) = "\\trenton\MyAssets"
End Sub


PI ProcessBook 3.2 (specifically, the ERD add-in) interprets calls to set the current context for MRD displays and handles them to make at least the simple displays work by providing an AF-equivalent path. This handling is provided when the MRD add-in is no longer present on the system.
More complex VBA scripts that do more than set the current context need to be rewritten to use the new AF-focused ERD add-in.