Control Techniques Epsilon EP-P Reference Manual page 21

the value you enter for the Offset or which Home Reference type you choose, there is always an offset inherent in the homing
process.
The user may either specify a desired offset or allow the drive to calculate an offset automatically. The drive calculates an
offset that guarantees that the motor will not have to backup to get to the offset position. This is very convenient for
unidirectional applications.
The Calculated offset is the distance travelled during deceleration ramp from the home velocity to a stop plus the distance
travelled at the home velocity for 800 usec. This extra distance is used to guarantee that the motor will not need to backup
after the deceleration ramp.
The Specified offset allows the user to choose an exact offset from the home reference. Once the home reference is detected,
the drive will do whatever is necessary to reach the offset position. This may be as simple as a deceleration to a stop, a
continuation at speed followed by a deceleration to a stop, or a deceleration followed by a move in the opposite direction.
To enter a Specified offset, select the Specified offset radio button. PowerTools Pro always displays the calculated offset value
as a reference.
Offset Examples
With a Calculated offset if the home reference is detected before the axis has reached its peak velocity, the axis will still
continue to the precise offset position, see Figure 12.
Figure 12:
If the home reference is detected after the axis has reached its peak velocity, the axis will decelerate to the precise offset
position.
Figure 13:
Two examples below show operation when the specified offset is greater or lesser than the calculated offset. This causes the
axis to continue on at speed before decelerating and stopping at the offset position, or backing up after the home sensor.
Epsilon EP-P Drive Reference Manual
Revision A4
Calculated Home Offset, Peak Velocity Not Reached
Calculated Home Offset, Peak Velocity Reached
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Calculated
Home Offset
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