Macro Programming Fundamentals

This is a revised edition (October 2023) of the first version published in January 2021.In this revised edition, certain modifications have been made at several places to make the description more elaborate and better. An Index is also added (in the Paperback version), for easy reference to the desired terms.This book is designed to give a quick and brief introduction to Macro Programming with reference to Fanuc Custom Macro B. Though it cannot make you an expert macro programmer, you will gain sufficient knowledge to at least interpret most of the macro programs written by others, and make necessary changes to these for your specific applications. For a serious study, one may refer to the author's other book on macro programming, "CNC Programming using Fanuc Custom Macro B," published by McGraw-Hill, New York.The book assumes only a basic understanding of simple G and M codes. May refer to author's another book, "SINHA's Handbook of Fanuc CNC Lathe: Programming, Tooling and Operation," for a deeper study of G codes, though not required for understanding macro programming. It is, however, recommended that one first develops a sound understanding of G-code programming before delving into the area of macro programming.The following excerpt from the System Variables chapter of the present book would give an idea of the depth of coverage as well as the way of presentation:Tool offsets (geometry and wear offsets)The specified geometry and wear offset values are stored in certain system variables. These variables are described below for recent versions of 0i series controls that use what is called Memory Type C. For an older control version (i.e., for those using Type A or Type B memory), refer to the machine manual.Typically, 64 (#2000 series) or 99 (#10000 series) offset numbers on a lathe (#10000 series can be used for 64 offset numbers also), and 200 (#2000 series) or 400 (#10000 series) offset numbers on a milling machine (#10000 series can be used for 200 offset numbers also) are available. It is, however, better to use the #10000 series, because its range is higher, and it can also be used for the lower range. #2000 series was used in older control versions. #10000 series was introduced for the purpose of increasing the offset numbers, which also allows for further increase beyond 99 (on lathes) and 400 (on milling machines) in future control versions.If an attempt is made to read/write undefined system variables, an error message, “ILLEGAL VARIABLE NUMBER,” is displayed. For example, a command such as #1 = #10065; would give an error message on a lathe with 64 available offsets. The tables given in Figs. 14−16 show the system variables for various tool-offset values on lathe and milling machines. These tables are copied from the author’s other book, CNC Programming using Fanuc Custom Macro B, published by McGraw-Hill, USA, which may be referred to for greater details.When offset setting is done, the corresponding system variables automatically store the respective offset distances. These are read/write variables, so it is also possible to change the offset values by modifying these variables. This can be done by executing, say, #15001 = 5; in MDI or memory mode, which will set the specified value (5, in this example) as the X-axis geometry-offset value corresponding to offset number 1 on a lathe. Read more