Standard homing

Standard homing is the most common method in practice of referencing machine axes.

Prerequisite

• Standard homing requires the presence of a reference cam.
• Standard homing realizes the cam play of the machine axis.
• Counter hardware with a latching input is generally required for a high referencing accuracy.

Timing

The timing of standard homing is in a maximum of three phases:

• Phase 1: travel to the reference cam
• Phase 2: travel from the reference cam
• Phase 3: travel to the reference cam with referencing

Figure 0-3 and Figure 0-4 show the sequence of standard homing.

Zero pulse

During referencing with a zero pulse, if corresponding hardware support is available the arrival of the zero pulse, provided the corresponding strobe input has been activated beforehand, leads to immediate latching of the counter status. Thus, the travel speed during referencing with evaluation of the zero pulse generally has no influence on the referencing accuracy.

A zero pulse is not necessary for standard homing. The zero pulse is evaluated in phase 3 during referencing, with the reference cam switch actuated.

Referencing exclusively with the reference cam without the zero pulse reduces referencing accuracy depending on the travel speed. Referencing without the zero pulse is shown in Figure 0-6.

The following speed-distance diagrams show the acceleration and deceleration phases in a simplified form as linear curves.