Class CircularMotionSyntax
- Namespace
- Hi.NcParsers.LogicSyntaxs
- Assembly
- HiMech.dll
Writes McArc motion for circular commands (ISO G02/G03). Detects motion mode from Flags, reads I/J/K center offsets or R radius from Parsing, computes arc center in program coordinates, and writes a one-shot MotionEvent (form + arc params) plus a modal MotionState (Term).
G02/G03 mode is modal (Group 01) — persists across blocks via Term. Arc parameters (I/J/K/R) are per-block and must be present in every arc block.
Must be placed before LinearMotionSyntax in the syntax chain. Both share the Group 01 motion slot; whichever writes a MotionEvent first claims it.
IsIjkAbsolute switches the I/J/K reading to absolute
center coordinates (Heidenhain DIN/ISO — the ISO twin of the
Klartext CC pole; the Heidenhain list sets it, every other brand
keeps the offset default). In that mode the center is modal: letters
not written in a block inherit the previous absolute pole
(AbsoluteIjkPoleKey, carried by the brand's
ModalCarrySyntax), a letter never
written falls back to the arc start's component, a letters-free
block that commands an endpoint continues the modal arc off the
pole (a flags-only block stays motionless), a G91 block reads
offsets again and breaks the pole chain, and the plane-normal letter
is a center coordinate — never the per-turn helix pitch. Behavior
mirrors HardNcLine.BuildArcNcArg +
ArcNcArg.GetCenterOrCenterOnBeginPlane (HiUniNc 3.1.152.2)
bit for bit.
public class CircularMotionSyntax : ISituNcSyntax, INcSyntax, IMakeXmlSource
- Inheritance
-
CircularMotionSyntax
- Implements
- Inherited Members
- Extension Methods
Examples
All cases below have the current block's ProgramXyz already
set (as a prior ProgramXyzSyntax would have produced)
and run with no #Previous:, so GetLastProgramXyz
returns Vec3d.Zero. The G17 XY plane is implicit
(no PlaneSelect section means
GetPlaneNormalDir(JsonObject) returns 2 — the
XY-plane default — so arc math runs with Z as the perpendicular axis).
G02 with I/J — quarter arc from (0,0,0) to (10,0,0)
around (5,0,0); I=5 J=0 are incremental offsets from start
to center. The G02 flag is consumed (Parsing removed
once empty); MotionState + MotionEvent are written:
{
"Parsing": { "Flags": ["G02"], "I": 5, "J": 0 },
"ProgramXyz": { "X": 10, "Y": 0, "Z": 0 }
}
#AfterBuild:
{
"ProgramXyz": { "X": 10, "Y": 0, "Z": 0 },
"MotionState": { "Term": "G02" },
"MotionEvent": {
"Form": "McArc",
"ArcCenter": { "X": 5, "Y": 0, "Z": 0 },
"IsCcw": false,
"AdditionalCircleNum": 0
}
}
Modal carry of G02: no motion flag on the current block but a
#Previous: MotionState.Term = "G02" tells us we are
still in circular mode. I/J on the current block describe the arc
the same way:
#Previous:
{ "MotionState": { "Term": "G02" } }
#BeforeBuild:
{
"Parsing": { "I": 5, "J": 0 },
"ProgramXyz": { "X": 10, "Y": 0, "Z": 0 }
}
#AfterBuild:
{
"ProgramXyz": { "X": 10, "Y": 0, "Z": 0 },
"MotionState": { "Term": "G02" },
"MotionEvent": {
"Form": "McArc",
"ArcCenter": { "X": 5, "Y": 0, "Z": 0 },
"IsCcw": false,
"AdditionalCircleNum": 0
}
}
No I/J/K/R on the block — the per-block arc data is missing, so
the syntax bails out early; the G02 flag stays in
Parsing.Flags for some other syntax to act on (or to surface
as residue if no one does):
#BeforeBuild:
{
"Parsing": { "Flags": ["G02"] },
"ProgramXyz": { "X": 10, "Y": 0, "Z": 0 }
}
#AfterBuild:
{
"Parsing": { "Flags": ["G02"] },
"ProgramXyz": { "X": 10, "Y": 0, "Z": 0 }
}
R-format degenerate (chord = 2R, semicircle): start (0,0,0)
→ end (10,0,0), R=5. perpDistSq resolves to 0 so the
computed center collapses to the chord midpoint (5,0,0); no
sqrt drift on this branch:
#BeforeBuild:
{
"Parsing": { "Flags": ["G02"], "R": 5 },
"ProgramXyz": { "X": 10, "Y": 0, "Z": 0 }
}
#AfterBuild:
{
"ProgramXyz": { "X": 10, "Y": 0, "Z": 0 },
"MotionState": { "Term": "G02" },
"MotionEvent": {
"Form": "McArc",
"ArcCenter": { "X": 5, "Y": 0, "Z": 0 },
"IsCcw": false,
"AdditionalCircleNum": 0
}
}
R-format non-trivial: G02 90° arc from (0,0,0) to
(10,10,0) with R=10. The center comes from the cross-product
+ sqrt + normalize path inside ResolveCenterFromSignedRadius(Vec3d, Vec3d, int, bool, double),
but for this particular axis-aligned chord the rounding errors
cancel and the center lands at exactly (10, 0, 0) — i.e.
no ULP drift here, in contrast to e.g.
McAbcCyclicPathSyntax's rad/deg round-trip:
#BeforeBuild:
{
"Parsing": { "Flags": ["G02"], "R": 10 },
"ProgramXyz": { "X": 10, "Y": 10, "Z": 0 }
}
#AfterBuild:
{
"ProgramXyz": { "X": 10, "Y": 10, "Z": 0 },
"MotionState": { "Term": "G02" },
"MotionEvent": {
"Form": "McArc",
"ArcCenter": { "X": 10, "Y": 0, "Z": 0 },
"IsCcw": false,
"AdditionalCircleNum": 0
}
}
G03 CCW with I/J — same geometry as case 0 (start (0,0,0),
end (10,0,0), I=5 J=0 → center (5,0,0)) but the G03
flag flips IsCcw to true. Direction is the only
differentiating output; arc-center math is unchanged:
#BeforeBuild:
{
"Parsing": { "Flags": ["G03"], "I": 5, "J": 0 },
"ProgramXyz": { "X": 10, "Y": 0, "Z": 0 }
}
#AfterBuild:
{
"ProgramXyz": { "X": 10, "Y": 0, "Z": 0 },
"MotionState": { "Term": "G03" },
"MotionEvent": {
"Form": "McArc",
"ArcCenter": { "X": 5, "Y": 0, "Z": 0 },
"IsCcw": true,
"AdditionalCircleNum": 0
}
}
Full circle G02 — start == end (both (0,0,0)), I=5 J=0
places center off-start at (5,0,0). Plane-restricted
closure (IsClosedOnPlane(Vec3d, Vec3d, int, double))
flips AdditionalCircleNum to 1 so a downstream motion
semantic knows to draw the closed loop:
#BeforeBuild:
{
"Parsing": { "Flags": ["G02"], "I": 5, "J": 0 },
"ProgramXyz": { "X": 0, "Y": 0, "Z": 0 }
}
#AfterBuild:
{
"ProgramXyz": { "X": 0, "Y": 0, "Z": 0 },
"MotionState": { "Term": "G02" },
"MotionEvent": {
"Form": "McArc",
"ArcCenter": { "X": 5, "Y": 0, "Z": 0 },
"IsCcw": false,
"AdditionalCircleNum": 1
}
}
Fanuc L parameter (helix turn count, 1-based) — L3 on a
start==end closed loop means three total turns, so
AdditionalCircleNum = L − 1 = 2. Matches the legacy
HardNc reading; the L parameter is consumed alongside I/J/K/R:
#BeforeBuild:
{
"Parsing": { "Flags": ["G02"], "I": 5, "J": 0, "L": 3 },
"ProgramXyz": { "X": 0, "Y": 0, "Z": 0 }
}
#AfterBuild:
{
"ProgramXyz": { "X": 0, "Y": 0, "Z": 0 },
"MotionState": { "Term": "G02" },
"MotionEvent": {
"Form": "McArc",
"ArcCenter": { "X": 5, "Y": 0, "Z": 0 },
"IsCcw": false,
"AdditionalCircleNum": 2
}
}
K-as-pitch helix on G17 (XY plane) — when the plane-normal axis
letter (K for G17, J for G18, I for G19) is present on an IJK-format
arc, it is the per-turn axial pitch, not a center offset. Here
K = −3 mm/turn over ΔZ = −9 mm gives
AdditionalCircleNum = floor(−9 / −3) = 3. The center stays
on the begin-plane (Z = 0) — ResolveCenterFromIjk zeros the
plane-normal component before adding to begin. Matches the legacy
HardNc reading:
#BeforeBuild:
{
"Parsing": { "Flags": ["G02"], "I": 5, "J": 0, "K": -3 },
"ProgramXyz": { "X": 0, "Y": 0, "Z": -9 }
}
#AfterBuild:
{
"ProgramXyz": { "X": 0, "Y": 0, "Z": -9 },
"MotionState": { "Term": "G02" },
"MotionEvent": {
"Form": "McArc",
"ArcCenter": { "X": 5, "Y": 0, "Z": 0 },
"IsCcw": false,
"AdditionalCircleNum": 3
}
}
Absolute I/J (IsIjkAbsolute = true on the SUT — the
Heidenhain DIN/ISO reading; values taken from a real production
program): I/J ARE the center's program coordinates, the center
is locked onto the begin plane (Z from the previous block), the
post-inheritance letters are recorded as the modal
AbsoluteIjkPole section and the event is stamped
IsIjkAbsolute for the NcOpt splition write-back (the arc
start comes from the predecessor's MachineCoordinateState —
the modal anchor GetLastProgramXyz reads; no transform chain
here, so it equals the program position):
#Previous:
{ "MachineCoordinateState": { "X": -23.958, "Y": -0.0965, "Z": 3.4338 } }
#BeforeBuild:
{
"Parsing": { "Flags": ["G02"], "I": -23.3261, "J": -1.2062 },
"ProgramXyz": { "X": -23.3253, "Y": 0.0708, "Z": 3.4338 }
}
#AfterBuild:
{
"ProgramXyz": { "X": -23.3253, "Y": 0.0708, "Z": 3.4338 },
"AbsoluteIjkPole": { "I": -23.3261, "J": -1.2062 },
"MotionState": { "Term": "G02" },
"MotionEvent": {
"Form": "McArc",
"ArcCenter": { "X": -23.3261, "Y": -1.2062, "Z": 3.4338 },
"IsCcw": false,
"AdditionalCircleNum": 0,
"IsIjkAbsolute": true
}
}
Absolute modal pole (the CC-pole twin): a continuation block writes
only J — the I component inherits the previous block's
AbsoluteIjkPole, the G03 mode continues via
#Previous: MotionState.Term, and the refreshed pole is
written back:
#Previous:
{
"MachineCoordinateState": { "X": -25.2297, "Y": 0.0704, "Z": 0 },
"AbsoluteIjkPole": { "I": -25.2029, "J": -0.9154 },
"MotionState": { "Term": "G03" }
}
#BeforeBuild:
{
"Parsing": { "J": -0.9154 },
"ProgramXyz": { "X": -24.9288, "Y": 0.5929, "Z": 0 }
}
#AfterBuild:
{
"ProgramXyz": { "X": -24.9288, "Y": 0.5929, "Z": 0 },
"AbsoluteIjkPole": { "I": -25.2029, "J": -0.9154 },
"MotionState": { "Term": "G03" },
"MotionEvent": {
"Form": "McArc",
"ArcCenter": { "X": -25.2029, "Y": -0.9154, "Z": 0 },
"IsCcw": true,
"AdditionalCircleNum": 0,
"IsIjkAbsolute": true
}
}
G91 on an IsIjkAbsolute SUT switches the block back to the
ordinary start-to-center offsets (center = begin + (I, J)), ignores
the inherited pole and BREAKS the pole chain — the emptied section
blocks the ModalCarry copy, so a later absolute block falls back to
the arc start (the preArcNcArg.IsIjkAbsolute check of
HardNcLine.BuildArcNcArg):
#Previous:
{
"MachineCoordinateState": { "X": 10, "Y": 0, "Z": 0 },
"AbsoluteIjkPole": { "I": -25.2029, "J": -0.9154 }
}
#BeforeBuild:
{
"Parsing": { "Flags": ["G02"], "I": 10, "J": 0 },
"Positioning": { "Term": "G91", "Mode": "Incremental" },
"ProgramXyz": { "X": 20, "Y": 10, "Z": 0 }
}
#AfterBuild:
{
"Positioning": { "Term": "G91", "Mode": "Incremental" },
"ProgramXyz": { "X": 20, "Y": 10, "Z": 0 },
"AbsoluteIjkPole": {},
"MotionState": { "Term": "G02" },
"MotionEvent": {
"Form": "McArc",
"ArcCenter": { "X": 20, "Y": 0, "Z": 0 },
"IsCcw": false,
"AdditionalCircleNum": 0
}
}
Constructors
CircularMotionSyntax()
Initializes a new instance with default settings.
public CircularMotionSyntax()
CircularMotionSyntax(XElement)
Initializes a new instance by deserializing from the given XML element.
public CircularMotionSyntax(XElement src)
Parameters
srcXElementSource XML element.
Fields
AbsoluteIjkPoleKey
Root-section key of the modal absolute-center pole (the letters of
the last absolute arc, post-inheritance — the SoftNc dual of
HardNcLine.ArcNcArg.Ijk). Written by every effective-absolute
arc block, emptied by a G91 arc block to break the chain, and
carried across intermediate blocks by the brand list's
ModalCarrySyntax Logic track. Kept
apart from HeidenhainCircleCenterSyntax's Klartext CC
section — the two dialect poles never share a key.
public const string AbsoluteIjkPoleKey = "AbsoluteIjkPole"
Field Value
Properties
IsIjkAbsolute
When true, I/J/K address the circle center as absolute program coordinates instead of start-to-center offsets, with the modal-pole / G91 semantics described on the class doc. Set by the Heidenhain list (DIN/ISO dialect); every other brand keeps the offset default.
public bool IsIjkAbsolute { get; set; }
Property Value
Name
Syntax kind name (typically the concrete type name).
public string Name { get; }
Property Value
XName
XML element name used to register this syntax with XFactory.
public static string XName { get; }
Property Value
Methods
Build(LazyLinkedListNode<SyntaxPiece>, List<INcDependency>, NcDiagnosticProgress)
Build syntax arrangement into the
syntaxPieceNode in-place.
public void Build(LazyLinkedListNode<SyntaxPiece> syntaxPieceNode, List<INcDependency> ncDependencyList, NcDiagnosticProgress ncDiagnosticProgress)
Parameters
syntaxPieceNodeLazyLinkedListNode<SyntaxPiece>ncDependencyListList<INcDependency>ncDiagnosticProgressNcDiagnosticProgress
MakeXmlSource(string, string, bool)
Creates an XML representation of the object. This method may also generate additional resources such as related files.
public XElement MakeXmlSource(string baseDirectory, string relFile, bool exhibitionOnly)
Parameters
baseDirectorystringThe base directory for resolving relative paths
relFilestringThe relative file path for the XML source
exhibitionOnlyboolif true, the extended file creation is suppressed.
Returns
- XElement
An XML element representing the object's state
Remarks
For the demand of easy moving source folder (especially project folder) without configuration file path corruption, the relative file path is applied.
The baseDirectory is typically the folder at the nearest configuration file folder.
Since the folder can be moving with the configuration file.
Reg(XFactory)
Registers this type's deserializer with the given XFactory
(or Default when factory is
null). Idempotent.
public static void Reg(XFactory factory = null)
Parameters
factoryXFactory