Homing without reversal

Homing without reversal

With homing without reversal and when the spindle is at standstill, the motion accelerates to the speed P-AXIS-00218 (vb_reflow) in the axis machine record. The spindle is accelerated not to the current limit but with default ramps. The rotation direction is initialised with the homing direction P-AXIS-00158 (ref_richt). When the spindle machine data is initialised, a check is made whether a preferred direction is specified for the spindle. If this does not match the specified homing direction, an error message is output.

If the spindle executes homing from endless rotation, it first accelerates or decelerates to the homing speed “vb_reflow” before being references. The referencing direction is identical to the endless rotation direction.

The spindle is set up with programmed speed and rapid traverse speed after homing without motion stop. This means that flying homing takes place. Positioning takes ´place in the direction in which homing was executed, even if this does not match the specified rotation direction.

Homing without spindle reversal can basically be executed in two methods. The method is defined by the value (TRUE/FALSE) of the variable P-AXIS-00156 (ref_ohne_nocken) in the axis machine record.

Parameterisation       ref_ohne_nocken     0

Read cam and zero pulse

This is used to trigger both the reference point cam and the zero pulse.

The reference point cam is triggered at the point when the ‘not operated’ edge changes. This means that, if the cam is currently operated, the spindle is rotated until the cam is not operated.

Parameterisation       ref_ohne_nocken     1

Only the zero pulse is used for triggering. This method can be used if only one zero pulse is triggered per spindle rotation.

Spindle modes (not SERCOS)

Homing with SERCOS drives

Drive-controlled homing is used for SERCOS drives. This means that the ACHSMODE_KEINE_AUTO_RPF bit must be set in the parameter “achs_mode” in the axis machine record for the spindles to prevent automatic referencing. The parameters “ref_ohne_rev” and “ref_ohne_nocken” are then no longer evaluated.

Notice

Before it is set up, a spindle with SERCOS drive must be subjected to explicit homing (via the automatic program or via a manual block). Otherwise an error message is output.

Spindle modes with SERCOS