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The SYMBOL_DESCRIPTION_FILE holds the Symbol Description Language (SDL) required to describe the symbols which will be generated to represent the part. It can be a plain text file or a comma seperated separated values (csv) file which is easy to edit an and manipulate in a spreadsheet editor. If the selected SDL file is a plain text file, partBuilder will create a .csv version of that file in the OUTPUT_FILES directory can be copied up to the part directory and used for future editing. The user might want to take advantage of this if they prefer to edit in a spreadsheet.
The SYMBOL_DESCRIPTION_FILE can be named anything, but is typcially typically named symbolOrder.txt or symbolOrder.csv. If the user wants to experiment with a new symbol layout, they can copy the existing file and change the name and then select the new one using the file browse button.
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If the SDL in the SYMBOL_DESCRIPTION_FILE contains LOOP_DIRECTIVES, PartBuilder will create an expanded copy of the file prefixed with exp_{file_name}. The user should be careful not to edit the expanded file because it gets regenerated each time the MAP_PINS_TO_SYMBOLS operation is run. The expanded file is a good place to look to make sure the SDL LOOP_DIRECTIVES are doing what they are intended to do. The expanded file has been moved to the OUTPUT_FILES directory in a future the v2.1.2 version of the PartBuilder tool to avoid confusion.