Sequence strategies for homing
The homing sequence of a machine axis is dependent on various factors, e.g.:
- Is a reference cam present?
- Is a zero pulse signal triggered?
- Should the reference cam be approached with cam clearance?
The various sequence strategies for homing are divided into the following methods and then described in greater detail:
- Default homing
- Flying homing for spindles
- Special homing methods
Default homing
For the default homing, it is assumed that a reference cam switch is present and the position counter can be latched by a cam or zero pulse signal.
The chronological sequence of default homing normally occurs in 3 phases:
- Phase 1: Move to reference cam
- Phase 2: Move away from reference cam
- Phase 3: Move to reference cam with referencing
The 3-phase default homing has 2 changes of direction. The motions can be parameterised at 2 different velocities.
Individual phases can be skipped with variants of this homing. Homing can then be reduced to a single phase. In this case, no change of direction is executed.
Flying homing for spindle axes
Flying homing is only available for spindle axes. The spindle axis must be referenced in order to set up a spindle axis, i.e. position with M19.
If the spindle axis is not referenced or if the reference point was lost, the spindle axis executes homing automatically. Flying homing is executed while the spindle axis is rotating without standstill.
Special homing methods
In special cases, default homing cannot be executed. The special homing methods below list further options to reference an axis according to the related parameterisation.
- Referencing with motion away from cam
- Referencing without reversal
- Referencing only with zero pulse without reference cam
- Referencing in the direction of the valid motion range by reversing the reference direction and reversing the cam signal level
- Referencing by motion to fixed stop