OpenNest/docs/cincinnati-post-output.md

Cincinnati Post Output Reference

Reference for the G-code structure emitted by OpenNest.Posts.Cincinnati. Every code listed here maps to a section in the Cincinnati Laser Programming Manual (docs/CINCINNATI LASER PROGRAMMING MANUAL.pdf, EM-423 R-02/11). Section numbers in parentheses (e.g. §1.52) refer to the manual.

If you add a new emission in the post, either cite the manual section it maps to, or flag it here as a known custom extension. "Custom code" in this project means something that is not documented in the manual but that the Cincinnati control is known to accept — none exist today and we should not introduce any without confirming the control behavior.

Overall file structure

A generated file contains, in order:

1. Main program (CincinnatiPreambleWriter.WriteMainProgram) Preamble, unit/mode setup, initial library, variable-declaration call, one M98 P<sheetSubNum> call per plate quantity, and M30 to end.

2. Variable declaration sub-program (CincinnatiPreambleWriter.WriteVariableDeclaration) Machine variables (#number = value) used across the nest, terminated with M99.

3. Sheet sub-programs (CincinnatiSheetWriter.Write), one per unique plate layout. A sheet sub-program contains the cutting sequence for a whole plate, either with features inlined or with M98 calls into part sub-programs.

4. Part sub-programs (CincinnatiPartSubprogramWriter.Write), one per unique (drawing, rotation) pair, only emitted when Config.UsePartSubprograms is enabled.

5. Hole sub-programs (CincinnatiPartSubprogramWriter.Write reused with a "HOLE" label), one per unique hole geometry keyed by radius and lead-in normal angle.

Sub-program bodies start with a :<subNum> label and end with M99.

Feature blocks

A "feature" is a single contour: lead-in → cut moves → lead-out. Each feature block in a sheet or sub-program output follows this order (CincinnatiFeatureWriter.Write):

1. G0 X_ Y_ — rapid to the pierce point (§1.00).
2. Optional part-name comment, only on the first feature of each part.
3. G89 P<library> — load process parameters (§2.89). P is a library file name; the (...) trailing comment carries speed-class info.
4. G84 (cut) or G85 (etch / no-pierce) — pierce and start cut, or start cut without pierce (§2.84 / §2.85).
5. M130 (ANTI DIVE OFF) — disable anti-dive, only if configured (§3.130).
6. Contour moves:
   • G41 (left) or G42 (right) kerf compensation on the first cut move (§1.41 / §1.42), suppressed for etch features.
   • G1 X_ Y_ [F<feedvar>] — linear cut move (§1.01). Feedrate references a machine variable such as #148 and is emitted only when it changes.
   • G2 X_ Y_ I_ J_ [F<feedvar>] (CW) or G3 (CCW) — arc (§1.02 / §1.03). I/J are incremental offsets from the current position to the center.
7. G40 — cancel kerf compensation (§1.40), only if it was applied.
8. M35 (or M135 if SpeedGas is enabled) — beam off (§3.35 / §3.135).
9. M131 (ANTI DIVE ON) — re-enable anti-dive (§3.131).
10. M47 or M47 P<distance> — raise Z-axis, unless this is the last feature on the sheet (§3.47). A leading / (block delete, §5.6) is prepended when the configured override distance exceeds the default.

Sheet sub-program and sheet-level feature calls add G92 X#5021 Y#5022 (§1.92) at the top so the local origin is anchored to the machine's current absolute position (#5021/#5022 are the machine X/Y system variables).

Sub-program call patterns

There are two distinct call-site patterns, depending on whether the call targets a whole-part sub-program or a hole sub-program.

Part sub-program call (WriteSubprogramCall)

Used when Config.UsePartSubprograms is enabled. The tool physically rapids to the part corner, then G92 sets the current position as the local origin, the sub-program executes in its own local coordinate frame, and G92 restores the original absolute position after return.

G0 X<left> Y<bottom>          ; rapid to part bounding box corner (§1.00)
(PART: <name>)
G92 X0 Y0                     ; set local origin at current position (§1.92)
M98 P<partSubNum> (<name>)    ; call the part sub-program (§3.98)
G92 X<left> Y<bottom>         ; restore the sheet coordinate system (§1.92)
M47                           ; head raise unless this is the last part (§3.47)

This pattern uses G92 because the tool is physically positioned at the part corner first. The sub-program's coordinates are part-local, so they are interpreted against the new origin until G92 restores the sheet frame.

Hole sub-program call (WriteHoleSubprogramCall)

Used for the SubProgramCall codes that a ContourCuttingStrategy emits for each circular hole. Unlike parts, we do not want a physical rapid to the hole center before calling — the sub-program's first rapid is the lead-in to the pierce point, and the machine should travel directly from the previous feature's end to that pierce.

G52 X<hole.x> Y<hole.y>       ; shift local origin to hole center (§1.52)
M98 P<holeSubNum>             ; call the shared hole sub-program (§3.98)
G52 X0 Y0                     ; restore the original coordinate system (§1.52)
M47                           ; head raise unless this is the last feature (§3.47)

G52 specifies the new origin in the current work coordinate system and — per §1.52 — "does not move the cutting nozzle". The hole sub-program is written in hole-local coordinates (origin at the hole center, produced by ContourCuttingStrategy), so its first G0 X_ Y_ resolves to hole + local in absolute terms. That is the first physical motion, and it takes the tool straight from wherever it was to the lead-in pierce point. G52 X0 Y0 cancels the shift after M99 returns control.

G-code reference

These are every G/M code the post emits, grouped by category. Anything here is documented in the programming manual. Anything not here should be audited the next time the post is edited.

Motion modes and contouring

Code	Description	Manual
G0 X_ Y_	Rapid traverse	§1.00
G1 X_ Y_ F_	Linear feedrate move	§1.01
G2 X_ Y_ I_ J_ F_	Clockwise arc	§1.02
G3 X_ Y_ I_ J_ F_	Counter-clockwise arc	§1.03

Units and coordinate mode

Code	Description	Manual
G20	Inch mode	§1.20
G21	Metric mode	§1.21
G90	Absolute mode	§1.90

Kerf compensation

Code	Description	Manual
G40	Cancel kerf compensation	§1.40
G41	Kerf compensation, left side	§1.41
G42	Kerf compensation, right side	§1.42

Work coordinate systems

Code	Description	Manual
G52 X_ Y_	Temporary local work coordinate offset. Does not move the tool. G52 X0 Y0 cancels.	§1.52
G92 X_ Y_	Sets the current tool position to (X, Y) in the work coordinate system, implicitly redefining the WCS origin.	§1.92

Exact stop

Code	Description	Manual
G61	Exact stop mode	§1.61

Cutting operations (custom Cincinnati G-codes)

Code	Description	Manual
G84	Pierce and start cut	§2.84
G85	Start cut without pierce (used for etch)	§2.85
G89 P<file>	Load process parameters from a library file	§2.89
G121	Enable non-stop cutting (Smart Rapids)	§2.121

Program flow

Code	Description	Manual
M30	End of main program with rewind	§3.30
M98 P_	Sub-program call. Takes only P and L — not X/Y.	§3.98
M99	Return from sub-program	§3.99

Machine state

Code	Description	Manual
M35	Beam off	§3.35
M42	Retract Z-axis	§3.42
M47 [P<dist>]	Raise Z-axis, optionally by a distance	§3.47
M50	Switch pallets	§3.50
M130	Anti-dive off	§3.130
M131	Anti-dive on	§3.131
M135	Discharge current off (keeps assist gas on)	§3.135

Comments, labels, and block delete

Syntax	Description	Manual
(text)	Inline comment	§5.4
:<number>	Sub-program label	§3.98
/<block>	Block delete — operator can toggle the line off	§5.6
N<number>	Line number, used by M99 P / GOTO targets	§5.5

System variables referenced

Variable	Description	Manual
#148	Default cut feedrate variable (used in F#148)	§2.89
#5021	Current machine X position	§6 (table of system variables)
#5022	Current machine Y position	§6 (table of system variables)

Project-defined variables start at Config.SheetWidthVariable / Config.SheetLengthVariable and at Config.UserVariableStart. Those ranges are documented in CincinnatiPostConfig.cs.