gcode

G-code parser and engine

• Library for parsing and executing G-code
• Tool to display G-code toolpath in the browser

G-code

The goal is to support multiple dialects of G-code.

• LinuxCNC
• BeagleG
• RepRap
• Smoothie

Code	Arguments	Description
G0	Fn.n Xn.n Yn.n Zn.n	rapid move
G1	Fn.n Xn.n Yn.n Zn.n	linear move (default)
G2	Fn.n Xn.n Yn.n Zn.n In.n Jn.n Kn.n	clockwise arc move with center
G2	Fn.n Xn.n Yn.n Zn.n Rn.n	clockwise arc move with radius
G3	Fn.n Xn.n Yn.n Zn.n In.n Jn.n Kn.n	counter-clockwise arc move with center
G3	Fn.n Xn.n Yn.n Zn.n Rn.n	counter-clockwise arc move with radius
G10	L2 Pn Xn.n Yn.n Zn.n	set coordinate system using absolute machine coordinates
G10	L20 Pn Xn.n Yn.n Zn.n	set coordinate system using relative machine coordinates
G17		XY plane selection (default)
G18		ZX plane selection
G19		YZ plane selection
G20		coordinates in inches
G21		coordinates in mm (default)
G28	Xn.n Yn.n Zn.n	go home
G28.1		set home
G30	Xn.n Yn.n Zn.n	go predefined position
G30.1		set predefined position
G53	G0 Fn.n Xn.n Yn.n Zn.n	rapid move using machine coordinates
G53	G1 Fn.n Xn.n Yn.n Zn.n	linear move using machine coordinates
G54		use coordinate system one (default)
G55		use coordinate system two
G56		use coordinate system three
G57		use coordinate system four
G58		use coordinate system five
G59		use coordinate system six
G59.1		use coordinate system seven
G59.2		use coordinate system eight
G59.3		use coordinate system nine
G90		absolute distance mode for X, Y, and, Z (default)
G90.1		absolute arc mode for I, J, and K
G91		relative distance mode for X, Y, and, Z
G91.1		relative arc mode for I, J, and K (default)
G92	Xn.n Yn.n Zn.n	set work position
G92.1		zero work position
G92.2		save work position, then zero
G92.3		restore saved work position
M2		end program
M3		spindle on clockwise
M4		spindle on counter-clockwise
M5		spindle off
M30		end program
Sn.n		spindle speed
Tn		select tool

Parameters

Parameter	Default	Persistent	Description
5161, 5162, 5163	0, 0, 0	yes	X, Y, Z for home position (G28)
5181, 5182, 5183	0, 0, 0	yes	X, Y, Z for predefined position (G30)
5210	0	yes	flag to control works offsets; 0 means off (G92)
5211, 5212, 5213	0, 0, 0	yes	X, Y, Z for work offsets (G92)
5220	1	yes	current coordinate system (G54 to G59.3)
5221, 5222, 5223	0, 0, 0	yes	X, Y, Z for coordinate system 1 offsets (G54)
5241, 5242, 5243	0, 0, 0	yes	X, Y, Z for coordinate system 2 offsets (G55)
5261, 5262, 5263	0, 0, 0	yes	X, Y, Z for coordinate system 3 offsets (G56)
5281, 5282, 5283	0, 0, 0	yes	X, Y, Z for coordinate system 4 offsets (G57)
5301, 5302, 5303	0, 0, 0	yes	X, Y, Z for coordinate system 5 offsets (G58)
5321, 5322, 5323	0, 0, 0	yes	X, Y, Z for coordinate system 6 offsets (G59)
5341, 5342, 5343	0, 0, 0	yes	X, Y, Z for coordinate system 7 offsets (G59.1)
5361, 5362, 5363	0, 0, 0	yes	X, Y, Z for coordinate system 8 offsets (G59.2)
5381, 5382, 5383	0, 0, 0	yes	X, Y, Z for coordinate system 9 offsets (G59.3)
5420, 5421, 5422		no	X, Y, Z for current position in active coordinate system
5599	1	no	flag to control output of (debug,...) comments; 0 means off

Syntax

Expression Syntax

<parameter> =
      '#' <integer>
    | '#' <name>
<expr> =
      <reference>
    | '[' <sub-expr> ']'
    | <number>
    | <name>
    | <string>
<sub-expr> =
      <number>
    | '-' <sub-expr>
    | '!' <sub-expr>
    | '[' <sub-expr> ']'
    | <sub-expr> <op> <sub-expr>
    | <reference>
    | <name>
    | <string>
    | <func> '[' [<sub-expr> [',' ...]] ']'
<op> = '+' '-' '*' '/'
    | '==' '!=' '<' '<=' '>' '>='
    | '&&' '||'
<reference> = '#'* <parameter>
<name> = '<' <name-char>+ '>'
<initial-name-char> = 'A' ... 'Z' | 'a' ... 'z' | '_'
<name-char> = <initial-name-char> | '0' ... '9'

LinuxCNC Specific Syntax

Comments which begin with msg, or debug, are written to standard output. For example, (msg,hello world!) will write hello world!.

Comments which begin with print, are written to standard error.

In addition, in debug, and print, comments, the values of parameters in the body of the comment will be expanded to their values. For example, the following code will write value of parameter 123: 456 to standard error.

#123=456
(print,value of parameter 123: #123)

BeagleG Specific Syntax

• IF expression THEN assignment
• IF expression THEN assignment ELSE assignment
• IF expression THEN assignment ELSEIF assignment ...
• IF expression THEN assignment ELSEIF assignment ... ELSE assignment
• WHILE expression DO
  line ...
  END

Alphanumeric parameters may be specified with and without bracketing < and > (eg. #param or #<param>).