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Limit specific BRD files to only using certain library paths?

bengelJF

I'm repackaging an existing design from an outside group and have received a schematic and footprint/padstack files.

By pure coincidence, some of the footprint names in the schematic matched up with our internal libraries and were placeable in the board file straightaway. However, I don't want this file to be able to access our internal libraries; I want it to only pull from a particular project-specific library.

I hop between projects pretty regularly, so I don't want to delete everything from my padpath and psmpath to limit my entire installation to the project-specific library. If I do this, I'd have to change them every time I hop to a different board, which could be multiple times a day.

Is there a way to tell a board file to only use specific libraries/file paths?

  • 0

    This is driven by your search paths stored in your SPB_Data/pcbenv/env file.

    You can either edit that text file or change your search paths around from Allegro.

    >Setup >Preferences

    Paths>  Library>

  • 0 in reply to Robert Finley

    Going through the setup menu is how I've gotten our libraries hooked up to my install of PCB Editor in the first place. It's clunky either way if I have to change these out on the fly multiple times a day, hence my question if there's a different/better way to handle these on-the-fly changes.

  • 0 in reply to bengelJF

    Yes.  I suggest replacing/swapping an entire Env file to be the easiest approach.   

    I believe having the wrong library isn't a problem until you netin a change.

  • +1

    Hi bengelJF, it is possible to place a brief SKILL file inside each design folder; in this file you can rewrite the library paths automatically when the design is opened. 

    This SKILL file is to be located in the same folder as your brd design, place the following lines of text in this; alter to suit your desired library paths:

    axlSetVariableFile("psmpath" "C:/SPB_Data/Lib/symbol" )
    axlSetVariableFile("padpath" "C:/SPB_Data/Lib/pad" )

    Save the above in a file named LibraryPaths.il as example.

    To complete the automation, go to your allegro.ilinit file located in the folder %home%/pcbenv. This SKILL initialisation file runs upon opening your design, therefore we should add the following line of code to allegro.ilinit : 

    load("LibraryPaths.il")

    In this way, any design can have specific individual paths loaded directly upon opening the board. Each design folder can have a different library path due its own version of the  LibraryPaths.il file. 

  • +1

    The solution we came up with was to use a relative path in the same directory as the .BRD file, e.g. "./Library", placed at the top of the padpath and psmpath lists. OrCAD goes through these lists from top to bottom when searching for footprints and padstacks, so by placing this at the top we tell it to look in this Library folder first.

    If we're working on a design from an external source, their footprints and padstacks go in this folder and are the first thing OrCAD encounters; if we're working on an internal project, we simply don't create that folder and it falls back on our regular libraries which are further down the list.

    The downside here is that you can still end up with internal footprints on an external project if it finds a matching item on an internal library, so we need to watch for that. The upside is that we don't need to create any scripts or customized files as long as we follow this setup.

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