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I think this is the manual you are looking for

 

http://content.heidenhain.de/doku/tnc_guide/pdf_files/TNC640/34059x-09/zyklen/892905-27.pdf

 

Cycle 421 is circular inside

Cycle 422 is circular outside

Cycle 423 is rectangular inside

Cycle 424 is rectangular outside

 

edit: begins att page 647

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