GOHOME - Return to original position

Command caption

How the command appears in the CLData command list:

GOHOME COUNT 2, MACHINE, X 34.725, Y 32, GEOM X 34.725, Y 32, Z 194, NX 0, NY 0, NZ 1, NW 0, MSF 0, Time 0.003

GOHOME command is used to move the tool to the machine zero. Commonly GOHOME command is translated into G28 code. Machine zero is defined by the CNC, postprocessor only receives the command code.

Access from sppx

Handler: program GoHome

Parameter	CLD array	Description
X Y Z	CLD[1] CLD[2] CLD[3]	Tooltip spatial coordinates, relative to the active workpiece CS
NX NY NZ NW	CLD[4] CLD[5] CLD[6] CLD[7]	Tool frame orientation, relative to the active workpiece CS. The way of orientation definition depend on setting inside Machine schema. It can be Euler angles in different conventions, Tool normal vector, quaternion or rotated vector.
MSF	CLD[8]	Machine state flags (flips). Actual for the robots and machines that can have multiple configurations of physical axes for same spatial position. See description in the next table.
Time	CLD[9]	The time of movement.
AxesCount	CLD[10]	Number of physical machine coordinates affected in this command.
r1	CLD[11]	Index of axis named Axis1Pos in the coordinates list.
Val1	CLD[12]	Value of the machine coordinate Axis1Pos.
r2	CLD[13]	Index of axis named Axis2Pos in the coordinates list.
Val2	CLD[14]	Value of the machine coordinate Axis2Pos.
…	…	…
rN	CLD[2*N+9]	Index of axis named AxisNPos in the coordinates list.
ValN	CLD[2*N+10]	Value of the machine coordinate AxisNPos.

Parameters available through the cmd operator

TCLDGoHome: ComplexType	Return machine to home position command
Axes: Array, Key="AxisID"	cmd.Ptr["Axes"] - An array of structures such as Axis. One command may include movement along several axes, the position of each is stored in this array.
Axis: ComplexType	cmd.Ptr["Axes"].Item[Index] or cmd.Ptr["Axes(AxisName)"] - Separate element of the Axes array. Contains information about moving on one machine axis. Access to the array elements can either by index or by key field. Here AxisName - the key field value, which must match the AxisID field value.
AxisID: String	cmd.Str["Axes(AxisName).AxisID"] - The identifier of the machine axis, for which the specified new position. Determined by the machine schema.
Value: Double	cmd.Flt["Axes(AxisName).Value"] - The new position of the machine axis, in which it moves.
Pos5D: ComplexType	cmd.Ptr["Pos5D"] - structure containing the coordinates that define the final position of the tool in space. Determines not only the position of the tuning point of the tool (the fields X, Y and Z - cartesian coordinates), but also the orientation of the tool relative to the current coordinate system (fields NX, NY, NZ and NW). Depending on the configuration of the system (defined in the scheme of machine), the tool orientation can be specified by: Normal vector n = (NX, NY, NZ), Spatial angles of rotation around the coordinate axes - the Euler angles (notation of Euler angles, ie the sequence of rotations is also specified in the settings) A = NX, B = NY, C = NZ. Quaternion q = (NX, NY, NZ, NW).
X: Double	cmd.Flt["Pos5D.X"] - X cartesian coordinate of the tool tip position.
Y: Double	cmd.Flt["Pos5D.Y"] - Y cartesian coordinate of the tool tip position.
Z: Double	cmd.Flt["Pos5D.Z"] - Z cartesian coordinate of the tool tip position.
NX: Double	cmd.Flt["Pos5D.NX"] - depending on the system configuration may be the NX component of the tool normal vector, the rotation angle around one of the coordinate axis, or the coefficient of the quaternion.
NY: Double	cmd.Flt["Pos5D.NY"] - depending on the system configuration may be the NY component of the tool normal vector, the rotation angle around one of the coordinate axis, or the coefficient of the quaternion.
NZ: Double	cmd.Flt["Pos5D.NZ"] - depending on the system configuration may be the NZ component of the tool normal vector, the rotation angle around one of the coordinate axis, or the coefficient of the quaternion.
NW: Double	cmd.Flt["Pos5D.NW"] - if you have chosen a method of orientation tool in the form of a quaternion is a fourth coefficient of quaternion.
MachineStateFlags: Integer	cmd.Ptr["MachineStateFlags"].Bit[i], i=(0..31). Integer number which is a bit field of 32 bits from 0 to 31. If there are several variants for the location of the machine axes, providing a specified position of the tool in space, every bit of this field determines the selection of one of the possible solutions. For example, a five-axis machine with A and C axes for most of the positions of the tool has two possible solutions - with a positive A-axis and with negative value of the A axis. Zero bit of this field will choose one of these solutions. For a standard six-axis articulated robot many of the tool positions in space can be provided with different combinations of three of its key joints positions (the base, elbow and wrist joints) giving a total of 8 possible solutions. In this case, the zero bit in this field will determine the position of the base, the first bit - the position of the elbow, and the third bit will be set the position of the robot's wrist. Thus, the meaning of each of this bits is determined entirely by the used machine schema. When using machines that do not need to use these flags, it is possible to disable the output of this parameter to CLData in the machine scheme.
Time: Double	The time of the movement in minutes.

The list of coordinates passed through CLData of GOHOME command is defined by the CAM system machine scheme.

Use the GMA array to process the GOHOME command. The properties of the GMA array are automatically assigned precalculated values of coordinate movement parameters. The command parameters are also available through the cmd operator.

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

program GoHome
  if CycleOn=1 then begin
    CycleOn = 0
    Cycle = 80
  end
  !OutBlock                 ! Output in block

  if Cmd.Ptr["Axes(AxisXPos)"]<>0 then begin
    X = 0; X@ = MaxReal
  end
  if Cmd.Ptr["Axes(AxisYPos)"]<>0 then begin
    Y = 0; Y@ = MaxReal
  end
  if Cmd.Ptr["Axes(AxisZPos)"]<>0 then begin
    Z = 0; Z@ = MaxReal
  end
  if Cmd.Ptr["Axes(AxisAPos)"]<>0 then begin
    A = 0; A@ = MaxReal
    HasAxisA = 1
  end
  if Cmd.Ptr["Axes(AxisBPos)"]<>0 then begin
    B = 0; B@ = MaxReal
    HasAxisB = 1
  end
  if Cmd.Ptr["Axes(AxisCPos)"]<>0 then begin
    C = 0; C@ = MaxReal
    HasAxisC = 1
  end
  if (X<>X@) or (Y<>Y@) or (Z<>Z@) or
     (A<>A@) or (B<>B@) or (C<>C@)
  then begin
    GFunc = 28; GFunc@ = MaxReal
    GAbsInc = 91
    OutBlock
    if NextCode<>CodeOfCmd("GoHome") then begin
      GAbsInc = 90
      OutBlock
    end
  end
end

Access from .NET

Handlers:

public override void OnBeforeMovement(ICLDMotionCommand cmd, CLDArray cld)   // group handler - before any motion command
public override void OnGoHome(ICLDGoHomeCommand cmd, CLDArray cld)
public override void OnAfterMovement(ICLDMotionCommand cmd, CLDArray cld)   // group handler - after any motion command

Inheritance: ICLDGoHomeCommand : ICLDMultiMotionCommand : 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.

Member	Type	Description
`cmd.EN`	`TInpRotation`	End normal or orientation of the movement in cartesian coordinate system. It can be normal vector, euler angles, quaternion etc. depend on the current machine schema settings.
`cmd.MSFlags`	`BitArray`	Machine state flags or robot flips which can help to define (together with cartesian coordinates) the specific state of the mechanism in case of redundancy. Which bit is responsible for which flag depends on the type and configuration of the equipment.
`cmd.Time`	`double`	Duration of the movement in minutes.
`cmd.AxesCount`	`int`	The count of axes that the movement contains inside the Axis[] list.
`cmd.Axis`	`ICLDMultiMotionAxesIndexer`	The list of the movement's axes [0..(AxesCount-1)].
`cmd.Axes`	`IEnumerable`	Axes' enumerator object for the movement to be possible to use covenient foreach syntax.
`cmd.HasAxis(...)`	`bool`	Returns "true" if the movement contains axis with the speciefed textual ID. Otherwise returns "false".
`cmd.EP`	`TInp3DPoint`	End point (X, Y, Z) of the movement

Example - OnGoHome (from the Fanuc (30i)_Mill_DN postprocessor):

public override void OnGoHome(ICLDGoHomeCommand cmd, CLDArray cld)
{
    foreach(CLDMultiMotionAxis ax in cmd.Axes) {
        if (ax.IsX) {
            nc.U.Show(0);
        } else if (ax.IsY) {
            nc.V.Show(0);
        } else if (ax.IsZ) {
            nc.W.Show(0);
        }
    }
    if (nc.U.Changed || nc.V.Changed || nc.W.Changed) {
        nc.GHome.Show(28);
        nc.Block.Out();
    }
}

GOHOME - Return to original position

Command caption

Access from sppx

Access from .NET

See also