Book excerpt: Until now, parametric programming has been the best-kept secret of CNC! This new book demystifies this simple yet sophisticated programming tool in an easy-to-understand tutorial format, and presents a comprehensive how-to of parametric programming from a user's point of view. Focusing on three of the most popular versions of parametric programming - Fanuc's custom macro B. Okuma's user task 2, and Fadal's macro - the book describes what parametric programming is, what it can do, and how it does it more efficiently than manual programming. Along with a host of program-simplifying techniques included in the book, you're treated to descriptions of how to write, set-up and run general subprograms simulate the addition of control options and integrate higher level programming capabilities at G-code level.