Technical data

Configuration
CPU 317T: Technology Functions
A5E00251798-03
4-53
Time-based execution of the reference point approach
• Phase 1: Synchronization to zero mark
The axis starts its reference point approach at the configured shutdown velocity
in the direction set in "Direction of reference point approach." Synchronization
with zero mark (phase 1) ends with the detection of the zero mark. The axis
position is set to the default value minus the homing position offset value
defined in "Homing position coordinate" (Mode = 0) or at input parameter
Position (Mode = 1.)
You can also monitor the distance an axis travels between the start of
reference point approach and zero mark detection by setting the "Max.
distance to zero mark" check box. Homing is canceled with error if the zero
mark is not detected between the start of reference point approach and the end
of the configured distance.
• Phase 2:
Approach to homing position
After the configured signal edge is detected, the axis accelerates / decelerates
at homing velocity to the homing point coordinate.
If a homing position offset was configured, the axis approaches the homing
position along the corresponding distance, starting at the synchronization
position. The traversing direction is determined by the sign of the homing point
offset value and by the length of the deceleration ramp after zero mark
detection, if the homing position lies within the deceleration ramp.
4.5.7.3 Passive/On-the-fly homing
Passive homing can be set in the "Passive homing" tab of the Axis > Homing
dialog box of S7T Config. The difference to active homing is, that the motion
required for homing is not initiated by the homing command.
Three passive homing modes are available:
• Passive homing with BERO (homing cam) and zero mark
• Passive homing with BERO only
• Passive homing with zero mark only.
Start of the homing function:
MC_Home
Mode = 2
Position = x
At the homing position, the current position is assigned the
value at input parameter Position.
After successful homing, the status Statusword.HomingDone = TRUE is indicated
in the technology DB of the axis.
Note
Note that not all drive components support all homing mode or measured signal evaluation
functions. For details, refer to the documentation of the drive components used.
Note
Triggering of zero mark or BERO monitoring during a passive homing operation is indicated
by a corresponding error message at the technology DB. The current axis motion is
terminated in this case.