CIRCLE - Circle movement

Command caption

How the command appears in the CLData command list:

CIRCLE XC xc, YC yc, ZC zc, R r, XE xe, YE ye, ZE ze

CIRCLE command represents movement along an arc. CIRCLE parameters are arc center, arc end point and arc radius. The sign of the radius defines the arc's direction. If the radius is positive then the arc has counter clockwise direction (G03 circle interpolation). If the radius is negative then the arc has clockwise direction (G02 circle interpolation). The arc's plane (G17/G18/G19) is defined by the current machining plane, set by the PLANE command.

Access from sppx

Handler: program Circle

The cld array is read by index or by name - in sppx by the typed short name (e.g. cld.X), in .NET by the same name as a string key (e.g. cld["X"]).

Parameter	CLD array	CLD name	Description
xc yc zc	CLD[1] CLD[2] CLD[3]	CLD.Xc CLD.Yc CLD.Zc	X, Y and Z coordinates of the arc center.
r	CLD[4]	CLD.R	Arc radius. If CLD.R > 0 then the arc is counter clockwise (G03), else if CLD.R < 0 then the arc is clockwise (G02).
xe ye ze	CLD[5] CLD[6] CLD[7]	CLD.Xe CLD.Ye CLD.Ze	X, Y and Z coordinates of the arc end point.
xs ys zs	CLD[8] CLD[9] CLD[10]	CLD.Xs CLD.Ys CLD.Zs	X, Y and Z coordinates of the arc start point
XcInc YcInc ZcInc	CLD[11] CLD[12] CLD[13]	CLD.XcInc CLD.YcInc CLD.ZcInc	X, Y and Z coordinates of the arc center point relative to the start point (I, J and K)
RAbs	CLD[14]	CLD.RAbs	Absolute value of the arc radius
RIso	CLD[15]	CLD.RIso	Arc radius in ISO variant - positive if angle less than 180 degrees and negative in other case
Dir	CLD[16]	CLD.Dir	Direction of the arc: 2-clockwise, 3-counterclockwise relative to the ISO plane G17-G19
Plane	CLD[17]	CLD.Plane	Plane of the arc, can take 6 values: 17, 18, 19, -17, -18, -19. Corresponds to the ISO planes G17-G19. A negative value means that the normal of the arc plane is inverse relative to the standard ISO plane.
Length	CLD[18]	CLD.Length	Size of the arc in current linear units
Ang	CLD[19]	CLD.Ang	Angle of the arc in degrees (0 to 360 degrees)
SAng	CLD[20]	CLD.SAng	Start angle of the arc relative to the first axis of the current plane
EAng	CLD[21]	CLD.EAng	End angle of the arc relative to the first axis of the current plane
HelixAng	CLD[22]	CLD.HelixAng	Angle of the helix in degrees. zero for planar circle, positive value for rising helix, negative value for descending helix.

Example (from the Fanuc (30i)_Mill postprocessor):

program Circle
  RSign: Integer
  
  if cld[4] > 0 then INTERP_ = 3 else INTERP_ = 2   ! G3/G2
  X = cld[5]                                  ! X,Y,Z in absolutes
  Y = cld[6]
  Z = cld[7]
  if CirclesThroughRadius>0 then begin
    call CheckCircleAngle(RSign)
    Rc = RSign*abs(CLD.R); Rc@ = MaxReal
  end else begin
    XC_ = cld[1] - XT_                            ! I,J,K in increments always
    YC_ = cld[2] - YT_
    ZC_ = cld[3] - ZT_
    XC_@ = MaxReal; ZC_@ = MaxReal
    if OperationIsLathe<>1 then
      YC_@ = MaxReal
    case Plane of
      17: ZC_@ = ZC_;
      18: YC_@ = YC_;
      19: XC_@ = XC_;
    end
  end
  case Plane of
    17: begin
      X@ = MaxReal;
      Y@ = MaxReal
    end
    18: begin
      X@ = MaxReal;
      Z@ = MaxReal
    end
    19: begin
      Y@ = MaxReal
      Z@ = MaxReal
    end
  end
  if IsRotaryInterpolation = 2 then begin
    Y = -Y/CylR/Pi*180
  end
  OutBlock                     ! output to NC block
  XT_ = cld[5]                 ! save current coordinates
  YT_ = cld[6]
  ZT_ = cld[7]
end

Access from .NET

Handlers (the specific handler plus the movement-group brackets that fire for every motion command):

public override void OnCircle(ICLDCircleCommand cmd, CLDArray cld)
public override void OnBeforeMovement(ICLDMotionCommand cmd, CLDArray cld)   // before any movement
public override void OnAfterMovement(ICLDMotionCommand cmd, CLDArray cld)    // after any movement

Inheritance: ICLDCircleCommand : ICLDMotionCommand : ICLDCommand.

Read the parameters from the strongly-typed cmd object (recommended); the raw cld[i] array (same indices as in sppx) and the named cmd[...] helpers are available too. The table lists the command's members, including those inherited from its base interfaces; the common ICLDCommand members (navigation, CLD, CLDFile, TechOperation, ...) are described in the CLData access model.

Property	Type	Description
`cmd.EP`	`TInp3DPoint`	End point (X, Y, Z) of the movement. (inherited from `ICLDMotionCommand`)
`cmd.SP`	`TInp3DPoint`	Arc start point (X, Y, Z).
`cmd.Center`	`TInp3DPoint`	Arc center point (X, Y, Z), absolute.
`cmd.IncCenter`	`TInp3DPoint`	Arc center point (I, J, K), incremental to the start point.
`cmd.R`	double	Arc radius; positive for CCW (G03), negative for CW (G02).
`cmd.RAbs`	double	Absolute value of the arc radius.
`cmd.RIso`	double	ISO-standard radius: positive if the arc angle is < 180 deg, negative if > 180 deg.
`cmd.Dir`	int	ISO direction code: `2` = CW (G2), `3` = CCW (G3).
`cmd.Plane`	int	Plane of the arc: `17, 18, 19, -17, -18, -19` (ISO G17-G19; negative = inverted normal).
`cmd.Length`	double	Length of the arc in current linear units.
`cmd.Ang`	double	Angle of the arc in degrees (0 to 360).
`cmd.SAng` `cmd.EAng`	double	Start / end angle of the arc relative to the first axis of the current plane.
`cmd.HelixAng`	double	Helix angle in degrees (0 planar, >0 rising, <0 descending).

Example (from the Fanuc 30i mill postprocessor):

public override void OnCircle(ICLDCircleCommand cmd, CLDArray cld)
{
    nc.GInterp.Show(cmd.Dir);                             // G02 / G03
    nc.X.v = cmd.EP.X;  nc.Y.v = cmd.EP.Y;  nc.Z.v = cmd.EP.Z;
    switch (Abs(cmd.Plane))                               // arc center as incremental I, J, K
    {
        case 17:
            nc.I.v = cmd.IncCenter.X;  nc.J.v = cmd.IncCenter.Y;
            nc.Block.Show(nc.X, nc.Y, nc.I, nc.J);
            break;
        case 18:
            nc.I.v = cmd.IncCenter.X;  nc.K.v = cmd.IncCenter.Z;
            nc.Block.Show(nc.X, nc.Z, nc.I, nc.K);
            break;
        case 19:
            nc.J.v = cmd.IncCenter.Y;  nc.K.v = cmd.IncCenter.Z;
            nc.Block.Show(nc.Y, nc.Z, nc.J, nc.K);
            break;
    }
}

CIRCLE - Circle movement

Command caption

Access from sppx

Access from .NET

See also