Important note: This manual describes several M and G codes which are relevant for the use of the Cyborg engraving machines.
The controller which we use handles a lot of other M and G codes, useful for other types of machinery, such as 3d-printers, plasma cutters, etc.
The codes which are of no use for an engraver without toolchanger are not described in this manual.

This chapter describes the input language, RS274/NGC.
The RS274/NGC language is based on lines of code. Each line (also called a “block”) may include commands to a machining center to do several different things. Lines of code may be collected in a file to make a program.
A typical line of code consists of an optional line number at the beginning followed by one or more “words.” A word consists of a letter followed by a number (or something that evaluates to a number).
A word may either give a command or provide an argument to a command. For example, “G1 X3” is a valid line of code with two words.
“G1” is a command meaning “move in a straight line at the programmed feed rate,” and “X3” provides an argument value (the value of X should be 3 at the end of the move).
Most RS274/NGC commands start with either G or M (for miscellaneous). The words for these commands are called “G codes” and “M codes.”
The RS274/NGC language has no indicator for the start of a program. The RS274/NGC language has two commands (M2 or M30), either of which ends a program.

A permissible line of input RS274/NGC code consists of the following, in order, with the restriction that there is a maximum (currently 256) to the number of characters allowed on a line.
• An optional line number.
• Any number of words, parameter settings, and comments.

Any input not explicitly allowed is illegal and will cause the Interpreter to signal an error.
Spaces and tabs are allowed anywhere on a line of code and do not change the meaning of the line, except inside comments.
This makes some strange-looking input legal. The line “g0x +0. 12 34y 7” is equivalent to “g0 x+0.1234 y7”, for example.
Blank lines are allowed in the input. They are to be ignored.
Input is case insensitive.

A line number is the letter N followed by an integer (with no sign) between 0 and 99999 written with no more than five digits (000009 is not OK, for example).
Line numbers may be repeated or used out of order, although normal practice is to avoid such usage.
Line numbers may also be skipped, and that is normal practice. A line number is not required to be used, but must be in the proper place if used.

A word is a letter other than N followed by a real value.
Words may begin with any of the letters shown in Table 3-2. The table includes N for completeness, even though, as defined above, line numbers are not words.
Several letters (I, J, K, L, P, and R) may have different meanings in different contexts.

The following rules are used for (explicit) numbers. In these rules a digit is a single character between 0 and 9.
• A number consists of (1) an optional plus or minus sign, followed by (2) zero to many digits, followed, possibly, by (3) one decimal point, followed by (4) zero to many digits - provided that there is at least one digit somewhere in the number
• There are two kinds of numbers: integers and decimals. An integer does not have a decimal point in it; a decimal does.
• Numbers may have any number of digits, subject to the limitation on line length. Only about seventeen significant figures will be retained, however (enough for all known applications).
• A non-zero number with no sign as the first character is assumed to be positive.

Notice that initial (before the decimal point and the first non-zero digit) and trailing (after the decimal point and the last non-zero digit) zeros are allowed but not required.
A number written with initial or trailing zeros will have the same value when it is read as if the extra zeros were not there.
Numbers used for specific purposes in RS274/NGC are often restricted to some finite set of values or some to some range of values.
In many uses, decimal numbers must be close to integers; this includes the values of indexes (for parameters and carousel slot numbers, for example), M codes, and G codes multiplied by ten.
A decimal number which is supposed be close to an integer is considered close enough if it is within 0.0001 of an integer.

Printable characters and white space inside parentheses is a comment. A left parenthesis always starts a comment. The comment ends at the first right parenthesis found thereafter.
Once a left parenthesis is placed on a line, a matching right parenthesis must appear before the end of the line. Comments may not be nested; it is an error if a left parenthesis is found after the start of a comment and before the end of the comment.
Here’s an example of a line containing a comment: “G80 M5 (stop motion)”. Comments do not cause a machining center to do anything.
A comment contains a message if “MSG,” appears after the left parenthesis and before any other printing characters. Variants of “MSG,” which include white space and lower case characters are allowed.
The rest of the characters before the right parenthesis are considered to be a message. Messages should be displayed on the message display device. Comments not containing messages need not be displayed there.

A line may have any number of G words, but two G words from the same modal group may not appear on the same line.
A line may have zero to four M words. Two M words from the same modal group may not appear on the same line.
For all other legal letters, a line may have only one word beginning with that letter.

In RS274/NGC, many commands cause a machining center to change from one mode to another, and the mode stays active until some other command changes it implicitly or explicitly.
Such commands are called “modal”. For example, if coolant is turned on, it stays on until it is explicitly turned off. The G codes for motion are also modal.
If a G1 (straight move) command is given on one line, for example, it will be executed again on the next line if one or more axis words are available on the line, unless an explicit command is given on that next line using the axis words or cancelling motion.
“Non-modal” codes have effect only on the lines on which they occur. For example, G4 (dwell) is non-modal.

Modal commands are arranged in sets called “modal groups”, and only one member of a modal group may be in force at any given time.
In general, a modal group contains commands for which it is logically impossible for two members to be in effect at the same time - like measure in inches vs. measure in millimeters.
A machining center may be in many modes at the same time, with one mode from each modal group being in effect. The modal groups are shown in the following table.

Modal Groups The modal groups for G codes are:

The modal groups for M codes are:

For several modal groups, when a machining center is ready to accept commands, one member of the group must be in effect. There are default settings for these modal groups. When the machining center is turned on or otherwise re-initialized, the default values are automatically in effect.

Group 1, the first group on the table, is a group of G codes for motion. One of these is always in effect. That one is called the current motion mode. It is an error to put a G-code from group 1 and a G-code from group 0 on the same line if both of them use axis words. If an axis word-using G-code from group 1 is implicitly in effect on a line (by having been activated on an earlier line), and a group 0 G-code that uses axis words appears on the line, the activity of the group 1 G-code is suspended for that line. The axis word-using G-codes from group 0 are G10, G28, G30, and G92.

G codes of the RS274/NGC language are shown in the table below and described in this Section. The descriptions contain command prototypes, set in bold type. In the command prototypes, three dots (…) stand for a real value. As described earlier, a real value may be (1) an explicit number, 4, for example, (2) an expression, [2+2], for example, (3) a parameter value, #88, for example, or (4) a unary function value, acos[0], for example.
In most cases, if axis words (any or all of X…, Y…, Z…, A…, B…, C…) are given, they specify a destination point. Axis numbers are in the currently active coordinate system, unless explicitly described as being in the absolute coordinate system.
Where axis words are optional, any omitted axes will have their current value. Any items in the command prototypes not explicitly described as optional are required. It is an error if a required item is omitted. In the prototypes, the values following letters are often given as explicit numbers. Unless stated otherwise, the explicit numbers can be real values. For example, G10 L2 could equally well be written G[2*5] L[1+1].
If the value of parameter 100 were 2, G10 L#100 would also mean the same. Using real values which are not explicit numbers as just shown in the examples is rarely useful.
If L… is written in a prototype the “…” will often be referred to as the “L number”. Similarly the “…” in H… may be called the “H number”, and so on for any other letter.

For rapid linear motion, program G0 X… Y… Z… A…, where all the axis words are optional, except that at least one must be used.
The G0 is optional if the current motion mode is G0. This will produce coordinated linear motion to the destination point at the current traverse rate (or slower if the machine will not go that fast). It is expected that cutting will not take place when a G0 command is executing.
It is an error if:
• All axis words are omitted.
If cutter radius compensation is active, the motion will differ from the above. If G53 is programmed on the same line, the motion will also differ.

G-codes

 <font 11pt/Calibri,sans-serif;;inherit;;inherit>meaning</font>|

 <font 11pt/Calibri,sans-serif;;inherit;;inherit>G0</font>|   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>rapid positioning</font> |

 <font 11pt/Calibri,sans-serif;;inherit;;inherit>G1</font>|   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>linear interpolation</font> |

 <font 11pt/Calibri,sans-serif;;inherit;;inherit>G2</font>|   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>circular/helical interpolation (clockwise)</font> |

 <font 11pt/Calibri,sans-serif;;inherit;;inherit>G3</font>|   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>circular/helical interpolation (counterclockwise)</font> |

 <font 11pt/Calibri,sans-serif;;inherit;;inherit>G4</font>|   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>dwell</font> |

 <font 11pt/Calibri,sans-serif;;inherit;;inherit>G10</font>|   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>coordinate system origin setting</font> |

 <font 11pt/Calibri,sans-serif;;inherit;;inherit>G17</font>|   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>XY-plane selection</font> |

 <font 11pt/Calibri,sans-serif;;inherit;;inherit>G18</font>|   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>XZ-plane selection</font> |

 <font 11pt/Calibri,sans-serif;;inherit;;inherit>G19</font>|   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>YZ-plane selection</font> |

 <font 11pt/Calibri,sans-serif;;inherit;;inherit>G20</font>|   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>inch system selection</font> |

 <font 11pt/Calibri,sans-serif;;inherit;;inherit>G21</font>|   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>millimeter system selection</font> |

 <font 11pt/Calibri,sans-serif;;inherit;;inherit>G28</font>|   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>move to park position 1, setup on variable page</font> |

 <font 11pt/Calibri,sans-serif;;inherit;;inherit>G30</font>|   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>move to park position 2, setup on variable page</font> |

 <font 11pt/Calibri,sans-serif;;inherit;;inherit>G33</font>|   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>Lathe, motion synchronized to spindle</font> |

 <font 11pt/Calibri,sans-serif;;inherit;;inherit>G38.2</font>|   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>straight probe</font> |

 <font 11pt/Calibri,sans-serif;;inherit;;inherit>G40</font>|   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>cancel cutter radius compensation</font> |

 <font 11pt/Calibri,sans-serif;;inherit;;inherit>G41</font>|   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>start cutter radius compensation left</font> |

 <font 11pt/Calibri,sans-serif;;inherit;;inherit>G42</font>|   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>start cutter radius compensation right</font> |

 <font 11pt/Calibri,sans-serif;;inherit;;inherit>G43</font>|   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>tool length offset (plus) , tool X offset for lathe</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G49</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>cancel tool length offset</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G53</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>motion in machine coordinate system</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G54</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>use preset work coordinate system 1</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G55</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>use preset work coordinate system 2</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G56</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>use preset work coordinate system 3</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G57</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>use preset work coordinate system 4</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G58</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>use preset work coordinate system 5</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G59</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>use preset work coordinate system 6</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G59.1</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>use preset work coordinate system 7</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G59.2</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>use preset work coordinate system 8</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G59.3</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>use preset work coordinate system 9</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G61</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>set path control mode: exact path</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G61.1</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>set path control mode: exact stop</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G64</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>set path control mode: continuous</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G68</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>XY rotation</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G76</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>Lathe, threading</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G80</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>cancel motion mode (including any canned cycle)</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G81</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>canned cycle: drilling</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G82</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>canned cycle: drilling with dwell</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G83</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>canned cycle: peck drilling</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G84</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>canned cycle: right hand tapping</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G85</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>canned cycle: boring, no dwell, feed out</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G86</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>canned cycle: boring, spindle stop, rapid out</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G87</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>canned cycle: back boring</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G88</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>canned cycle: boring, spindle stop, manual out</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G89</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>canned cycle: boring, dwell, feed out</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G90</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>absolute distance mode</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G91</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>incremental distance mode</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G92</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>offset coordinate systems and set parameters</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G92.1</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>cancel offset coordinate systems and set parameters to zero</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G92.2</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>cancel offset coordinate systems but do not reset parameters</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G92.3</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>apply parameters to offset coordinate systems</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G93</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>inverse time feed rate mode</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G94</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>units per minute feed rate mode</font> |

 <font 11pt/Calibri,sans-serif;;black;;inherit>G98</font> |   \\
 <font 11pt/Calibri,sans-serif;;black;;inherit>initial level return in canned cycles</font> |

Continue to the table of contents.