Description on Schematic BOM report not showing up

[IvanBarankevich]

For some reason I am having a hard time getting my description from showing up on one specific item. I am attaching the symbol. Can someone please tell me what I did wrong with this one. Everything else seems to show up no problem.

Thanks

[dougmcalexander]

This is usually a result of someone typing in a Catalog number instead of using Lookup to assign it.  If so much as a space is missing, or present when it should not be, or a dash is misplaced, or a letter O is accidentally substituted for number 0, the BOM report will not find a match.  It will generate a report and include whatever MFG and CAT values were typed in, but when it searches the Catalog Database for the part, in order to extract the description, it will not find a match and will thus leave the description field blank.

[IvanBarankevich]

This i know and never type in the part number or manufacturer and always use the lookup. For some reason it's this specific Item that gives me grief every time. All others seem to work without a problem. At one time I found a post here that said I needed to add some kind of XDATA and that seemed to work. But I can't find that post anymore and can't remember what it was. But that solved the problem for the project I would like to know how I can fix that block to work every time.

Thanks

[IvanBarankevich]

I just found that post, it tells me to add the VIA_WD_WDBLKNAM to the XDATA of the symbol once I add that it works no problem. Now my question is how do I make the symbol have this added automatically. Because all my other symbols work without a problem.

[dougmcalexander]

Okay, I see your problem.  Your custom heater symbol is named HHT1_002.dwg.  And that is a reasonable name, given that heaters are normally tagged as HT.  However, by default, not all part numbers come from tables named exactly as the tag.  This is partly due to the changes in symbols tags between JIC and NFPA over the years.  For example, transformers are tagged as T under NFPA-79, but the part numbers come from table XF, an old designation for transformer.  Transformer symbol blocks are named HXF1, etc., an old naming convention, so the table is named XF.  The software normally expects the tables to be named with two letters (except for terminals and PLC modules) so the letter T would not be appropriate for the transformer table, unless you used something like _T or T_, and you named your transformer symbols in similar fashion.  Remember that the 2nd and 3rd character of the bock name tell the part number Lookup which table to open.

Until the IEC instituted the option of two-letter component class designations, they used such letters as E for a heating element, H for an indicator lamp, and K for a control relay.   But the IEC symbol library in AutoCAD Electrical uses the same block naming convention for all libraries, derived from legacy naming conventions in the U.S. dating back to the early days of this software.  So in order to ensure that the Lookup works consistently, to support the Library Swap utility, and to allow a new version of AutoCAD Electrical to be compatible with drawings from the earliest days of the software, the symbol names are still based upon legacy standards.

So, now that we understand why the infrastructure functions as it does, let's tackle the heater issue.  By default, heater part numbers are stored in the RE table of the Catalog Database (see attached screen capture).  This is because the older symbol libraries don't actually contain a heater symbol.  Most of us just used a resistor symbol, since a heater is really a resistor that doesn't normally fail when it glows.  The more up-to-date NFPA library includes heater symbols, but again, since they are actually a type of resistor, their block names are HRE1HT and HRE1HTALT for the alternate version (see attached screen capture).  Your custom block is named HHT1_002 and there is no table named HT (unless you add one, but read on).  

This scenario can be easily solved and you have multiple options.  You can rename your block to HRE1_002.dwg and store your heater part numbers in the resistor table, so the Lookup finds the RE table to extract the description from.  You can add a WDBLKNAM attribute to the block with a value of RE and the software will see this as an override of its normal use of the 2nd and 3rd character of the block name to determine the Lookup table.  You do not need to fool with xdata, though that will provide a quick fix for symbols already inserted into your drawings.  But even then, I recommend using the Add Attribute utility instead (see attached screen capture).  There is a third option.  You can add a new table to the Catalog database. Name the table HT.  Do not add the table via MS Access because it will most likely not get formatted correctly for use by AutoCAD Electrical.  There is a utility under the Project Other Tools menu tab that adds a table for you and it properly formats the table for use by AutoCAD Electrical.  In fact, the first time you tried a Lookup with this new block, the software should have offered to create an HT table for you.  There is even a fourth option.  You can set your Project Properties to use the MISC_CAT table if no component-specific table is found, and the Lookup will automatically jump to the MISC_CAT table for custom symbols that do not match up to an existing table name.  This option keeps you from having to do anything to your existing blocks.  Just add your heater part numbers to the MISC_CAT table.  I usually recommend this method for any new block that isn't covered by an existing table.  This avoids the possibility that someone might accidentally create a new table that isn't properly named and formatted, which can hinder future migration of your parts data into a newer version of AutoCAD Electrical's Catalog database.

[IvanBarankevich]

The interesting thing is that I did add the table called HT using autocad when it asked me to add the table and let it create it for me, but apparently something went wrong with it because both parts that are located on it are not being found when I put the in unless I add the VIA_WD_WDBLKNAM with the text HT for value. When I do add it it finds them without a problem.

[dougmcalexander]

That is odd. But again, it doesn't hurt to add the WDBLKNAM attribute to the block. Consider adding it to the block in your library, not just adding it to those that are inserted already. You can then use the Update Block utility to update all of those that are already inserted into drawings at once. Be sure to enter HT as the value for the WDBLKNAM attribute, since you want the software to use the HT table.

[David.Borchardt]

This can also happen when you use the catalog look-up. If there is a space at the end of the catalog entry in the database.