NC file check and fix

Why a correct program will not go into the machine

A program file is a text file. Besides the characters you see, it has invisible characters that each system uses differently. A text editor on a computer shows every kind the same, but a controller is not as forgiving.

• Line endings: Windows ends a line with two characters, CR LF; Unix and Linux use LF alone; old Macs used CR alone. In the ISO code that Fanuc-type controllers use, EOB (end of block) is the LF character. Most controllers skip the CR, but some models and transfer settings do not.
• Mixed line endings usually come from joining programs from several sources, or editing a file with several programs.
• BOM (byte order mark): three invisible bytes that some programs, such as older Notepad, put at the very start of a file to mark it as UTF-8. Editors hide them so the file looks normal, but the controller reads stray characters before the % and raises an alarm or refuses the file. The fixer always removes it.
• Non-ASCII text in comments: most controllers take ASCII only, so Thai, accented or other non-ASCII letters in brackets can stop the file going in. Files saved by older Windows programs may be in a local code page such as TIS-620.
• The % marks: over a cable, and with some memory card methods, the controller starts reading after the first % and stops at the second.

What the fixer changes

• Only the line endings, spaces, letter case, comments and % lines, as chosen. It does not change any address letter or number in the code.
• Lower-case letters in comments are left alone unless chosen. Most newer controllers take them; if an older machine raises an alarm on lines with lower-case comments, choose to change them too.
• The BOM and invisible control characters (such as Ctrl-Z) are always removed, and a line ending is added after the last line.
• The result is plain ASCII when no non-ASCII text is left. If comments are kept, the file is UTF-8 without a BOM.
• A line left with nothing but a removed comment is removed entirely.
• Press Fixed file above the file view to see the result before downloading.

Limits

• It does not know what your machine takes. When sending over a cable (RS-232) or with DNC software, the sending program's settings, such as the line ending, must match the machine's parameters. See the machine's manual or ask whoever looks after it.
• It does not check the program itself. Use the backplot to see the toolpath.
• Text after the closing % is not removed, because it may be a subprogram that you need to move above the % yourself.
• Stray characters in the code must be fixed by hand, such as Thai digits (X๑๐) or full-width letters typed with a Chinese or Japanese keyboard (Ｇ０１). The fixer never changes letters or numbers in the code, so no value in the program changes without someone checking it; fix the lines it lists. The exception is special spaces copied from a web page or Word, which become ordinary spaces.
• Comments after ;: the checker knows only Fanuc-style comments in brackets, such as (DRILL 8.5). Comments after ;, used by some controllers such as Siemens, are checked as code, so non-ASCII text in them is listed as something to fix by hand; the option to remove comments does not affect them, and their letters are made capital if that is chosen.