Homing for NC spindles

To execute spindle positioning, the coordinate zero point must be synchronised with the signals of the actual value measuring system by a reference marker. With spindles, this can take place during endless rotation without standstill. For example, the zero point passage of the actual value encoder is used.

Automatic homing

If no homing took place for the spindle, it is executed automatically before positioning with M19 takes place or if positioning or stopping the spindle with M05 takes place after the control limit speed is exceeded (see the figure in section Spindle operation modes).

Notice

With digital drive systems (e.g. SERCOS), drive-controlled homing is executed using the command (G74). Automatic homing is not possible. This must be deactivated by axis parameter P-AXIS-00015.

Programming

Example

Homing for NC spindles

G74 S1 or S[G74]

Homing spindles and other axes can be started simultaneously but is otherwise not synchronised.

1. Homing the spindle starts simultaneously with Y axis homing:

     N10    G74  X2  Y1  S1

2nd Same as 1. The system continues to the next NC block without waiting until the spindle is referenced so that the X axis is referenced quasi simultaneously:

     N10   G74  S1

     N15   G74  X1  Y2

3rd Axes X and Y are first referenced. Spindle referencing then starts:

     N10   G74  X1  Y2

     N15   G74  S1

A detailed description of homing for axes and spindles is contained in the documentation [FCT-M1].