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 (EM-423 R-02/11). Section numbers in parentheses (e.g. §1.52) refer to that edition. Obtain the applicable manual from Cincinnati; vendor manuals are not bundled because redistribution permission has not been established.

This is a project-written implementation reference, not a replacement for the machine's programming, operating, or safety documentation. Keep vendor PDFs and full-text extracts outside source control; do not re-add them without permission. For the separate CI Fiber post, see CI Fiber output.

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. Parts, cut-offs included, post in plate order, which is the cut sequence set by manual, cut-first or automatic sequencing; the post never reorders them.

4. Part sub-programs (CincinnatiPartSubprogramWriter.Write), one per unique posted part toolpath, only emitted when Config.UsePartSubprograms is enabled. Parts share a sub-program only when they have the same drawing name and their normalized programs (lead-ins, hole calls and suppression included) post identically, so parts of one drawing and rotation with different lead-ins get their own sub-programs.

5. Hole sub-programs (CincinnatiPartSubprogramWriter.Write reused with a "HOLE" label), one per unique posted hole toolpath. Calls are matched to sub-programs by their program reference, never by call id: lead-in planning numbers holes 1, 2, ... within each drawing, so ids collide across drawings. Hole programs are stored incremental; the post writes absolute-mode copies (everything posts under G90) and leaves the nest's programs unchanged.

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

The post reads part programs through absolute-mode copies and never changes the nest: an incremental part program stays incremental after posting.

Sheet header

Each sheet sub-program re-anchors the work frame with G92 X#5021 Y#5022 (§1.92; #5021/#5022 are the machine X/Y system variables), loads the cut library with G89 P<library> (§2.89) when one resolved, and raises the head with M47. When Config.UseLineNumbers is on it then posts GOTO<FeatureLineNumberStart>( Goto Feature ) (§5.5), which targets the sheet's first feature line; the operator edits it to restart at another feature. Without line numbers there is no target, so no GOTO is posted.

Suppressed moves

Moves with Motion.Suppressed set are not cut, as in the CI Fiber post and the cut simulation. When cutting resumes after a suppressed run, the post ends the feature and starts a new one with a rapid to the run's end point, so the gap is crossed with the beam off. Rapids left with nothing to cut, and hole calls whose moves are all suppressed, are dropped.

Cut library selection

MaterialLibraryResolver picks the first MaterialLibraries entry matching the nest material, thickness within 0.001 and assist gas (Nest.AssistGas, else Config.DefaultAssistGas). Before the configuration dialog opens, PrepareForNest pre-selects that same entry as SelectedLibrary, or clears the selection when nothing matches; it never substitutes another gas or thickness. A SelectedLibrary the operator then picks overrides auto-resolution.

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. With no resolved library the post writes (WARNING: No library found) instead.
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. Head raise before the rapid to the next feature, unless this is the last feature on the sheet (§3.47). See Head raises.

Head-locked cut-off overcuts

A cut-off with a head-locked overcut (see automatic cutoffs) writes HeadHeightLockCode where its program locks the head and HeadHeightUnlockCode where it unlocks, each as its own block inside the feature loop: after the pierce, between cut moves. A feature that ends with the head locked gets no head raise, so the rapid back along the overcut keeps the head down; the next feature pierces at the nominal edge and then unlocks before it cuts toward the origin. Both codes are empty by default. A nest with a head-locked cut-off is refused before anything is written while either is empty (HeadHeightLock.EnsurePostable). The codes and the machine's behavior when it pierces, beams off or rapids with the head locked are unconfirmed; enter and verify them on the machine before relying on the overcut.

Head raises (M47)

Every raise is written at the end of the feature it follows, before the rapid that leaves it, and there is exactly one raise per rapid. The block is chosen in this order (CincinnatiHeadRaise):

1. M47 P<SafetyHeadraiseDistance> (Safety Headraise) when the rapid travel to the next pierce exceeds SafetyHeadraiseRapidDistance (program units, default 12) and both settings are set. Long rapids cross more of a warped sheet, so the head goes higher; which part or drawing comes next does not matter. Unknown travel (a hole call's rapid inside a part sub-program) never takes it.
2. Otherwise the M47 mode for the feature just cut: ExteriorM47 after a part's exterior, InteriorM47 after anything else.
   • Always: M47.
   • BlockDelete: /M47; the operator can skip it with block delete (§5.6).
   • Auto: M47 when the rapid travel to the next pierce exceeds M47OverrideDistanceThreshold (program units), /M47 when it does not. With no threshold, Auto always posts M47.
   • None: no raise.

The exterior is the cut feature whose cut moves (lead-in and lead-out moves excluded) span the extents of all of the part's cut moves; etch features and hole calls are never exterior, and a part whose outline is cut in several features has no exterior. The raise after a part sub-program call follows ExteriorM47. These rules are this project's interpretation of the settings, not vendor-documented behavior.

Hole calls (see below) write M47, or the safety raise, after G52 X0 Y0 regardless of the M47 mode.

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 corner of the part's toolpath, G92 sets that position as the local origin, and the sub-program executes in its own local coordinate frame. After it returns, the tool is wherever the sub-program's last feature ended, so the head is raised, the tool rapids back to local 0,0 (the corner) and G92 gives that point its sheet coordinates again.

G0 X<left> Y<bottom>          ; rapid to the toolpath 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)
M47                           ; head raise for the rapids that follow (§3.47)
G0 X0 Y0                      ; back to the corner (§1.00)
G92 X<left> Y<bottom>         ; restore the sheet coordinate system (§1.92)

The last part on a sheet stops after M98: nothing moves before the next sheet re-anchors with G92 X#5021 Y#5022. The sub-program's last feature posts no raise, so the raise after the call is the only one before the rapids, chosen by the head raise rules.

This pattern uses G92 rather than G52 because hole calls inside a part sub-program use G52 themselves, and a nested G52 would replace the part shift instead of adding to it.

Hole sub-program call (CincinnatiHoleCallWriter.Write)

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)
( PART: <name> )              ; only when the hole is the part's first feature
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)

<hole> is the hole center in the calling program's frame: the part location plus the call offset in a sheet sub-program, or the call offset alone inside a part sub-program (whose frame is already the part's). A hole call followed by a long rapid takes the safety head raise on that call's M47, as an ordinary feature would.

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.