Nate Holt's Blog

November 19, 2009

Overview of Simple BOM reporting – AutoCAD Electrical

Filed under: Electrical, Tutorials — nateholt @ 1:20 am

Brief overview of how two different databases are queried to create various AutoCAD Electrical BOM reports.

This question comes up from time to time, most recently today. Here is a brief summary in the form of screenshots illustrating how a component on an AutoCAD Electrical drawing (a mechanical footprint symbol on a panel layout drawing) finds its way on to a BOM report. This illustrates just a simple, straightforward catalog assignment – without “ASSYCODE” and without “Multi-BOM” catalog assignments (future posting!).

A small portion of one drawing, DEMO08.dwg, which is part of a sample AutoCAD Electrical project drawing set “WDDEMO”, is shown below.

AutoCAD Electrical maintains a “scratch” database file, in Microsoft Access format, that follows what is going on in the project drawing set (it does not drive it, it follows it). The above mechanical footprint component, SS433 on drawing DEMO08.dwg of the project, shows up in the “PNLCOMP” table of the scratch database file for this project.

 The scratch database file name is the same name as the active AutoCAD Electrical project name but with an “.mdb” extension. It is saved in the local AutoCAD Electrical “user” folder. The full name can be displayed by typing this at the AutoCAD “Command:” prompt.

 Command:  (c:wd_mdb_get_proj_scratch_dbnam nil) [Enter]

 Here is a screenshot of the above panel component in the PNLCOMP table of the project scratch database:

And here’s another screenshot of the above record with a few other fields exposed. These fields are used to guide AutoCAD Electrical’s BOM reporting command to the appropriate “table” in the catalog lookup database file DEFAULT_CAT.mdb (shown shortly).

The actual table name that the BOM report queries for this “SS433” symbol’s catalog description information is influenced by the WDBLKNAM value shown above. See this posting for a description of how auto-table selection works.

Ultimately, the BOM reporting goes to table “SS” in the DEFAULT_CAT.mdb file. It uses the MFG/CAT attribute values carried on the panel footprint symbol (and extracted into the PNLCOMP table shown above) to find the appropriate record in the “SS” table shown here:

And now the BOM reporting command merges the data in the record above with the data from the scratch database file. It is formatted into the report and shows up as an entry here in the BOM Report Generator dialog ( ! ):

Now, at this point, you can write the report out to a file (in various formats) or insert the report as a “smart” table on to your AutoCAD drawing.



  1. […] Overview of Simple BOM reporting Enhanced wire number tags based on connected components PLC I/O Drawing Generator – Pre-defining wire numbers […]

    Pingback by Index of AutoCAD Electrical Utilities – April 2006 through September 2009 « AutoCAD Electrical Etcetera — November 19, 2009 @ 1:38 am

  2. Is it possible to ‘do this in reverse’?

    I have a drawing set with a complete BOM output to excel and all of the drawings but all of the catalog entries were lost with a computer problem.

    The modified catalogs were lost. And a project specific database needed to be created in any case.

    I WISH I had seen this before the catalogs were lost!

    Is it possible to automate if even partially a rebuilding of a project specific catalog database using a BOM output to excel and the drawing set?

    thanks for any tips or input whatsoever

    Comment by Jeff — December 1, 2009 @ 2:17 pm

    • Hi Jeff,

      Yeah, most anything is possible if willing to devote enough time/effort to write the utility and test/debug it to get it working. Your BOM report could be parsed and compared with what’s already in your default_cat.mdb file. For records not found, new ones could be created and pushed into the generic catalog lookup file.

      I don’t think I have anything pre-made you could use as a starting point for such a utility. Probably have to start from “scratch”.

      If this is a serious issue for your company and you want some estimate of what effort it would take, please let me know.


      Comment by nateholt — December 31, 2009 @ 10:56 am

      • Hi Nate,

        Yes it is possible! I can see that now that I have completed doing the process in a semi-automated fashion; A combination of Excel and MS Access and time. (Im most comfortable in Excel)

        I learned a lot going through creating my own project specific database. At some point I’ll want to merge it back into my own default_cat since these parts will be used again … but I will study that one.

        So for me the problem is now solved and lessons learned. The files used by Autocad are now part of my regular backup.

        Thanks for such a great resource,

        -Jeff Bassler

        Comment by Jeff — December 31, 2009 @ 1:36 pm

  3. THANK YOU. I’ve been trying to figure this out forever and this is the first post that has addressed this.

    Would like to know the answer to Jeff’s question as well (whether or not you can do this in reverse).

    Comment by CAD Drawing — December 31, 2009 @ 10:20 am

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