CNC Macro Programming

Typical macro program

O8001 (MACRO);
#24 = 25.4;
#12 = #12/2;
G90 G00 X[#24+#12] Y#25;
#200 = #4/#3;
#201 = FIX[#200];
IF[#200 EQ #201] GOTO999;
G90 G01 Z-#4;
G03 I-#12;
N999 G90 G00 Z0;
M99;
%

A Quick Overview

A typical macro program looks quite a bit different from standard G-Code. Once it has been broken down it makes a lot more sense.

The numbers that start with a hash (#) symbol are variables. These are used to store values. We can define these variables by typing #100 = 10; It's as simple as that.
We can also use them to store answers to maths equations that can be used within the program.

For example: '#100 = 1 + 2' This little equation would make #100 equal to 3.

If we were then to say #200 = #100 + #100; then #200 would be equal to 6.

We can also add logic to our program by using 'IF' statements such as 'IF [A CONDITION IS TRUE] THEN [DO SOMETHING]'

So using our same variables we could say: IF [#100 EQ 3] GOTO 10;

EQ means 'equal to' so #100 IS equal to 3.
This statement would be true therefore the program would jump to N10 line number. If it was not equal to 3 the computer would skip the GOTO statement and continue to read the rest of the program after this line.