Reference To Current Position - Delta ASDA Series Application Notes

Introduction of PR Operation

1.2.2.5 Reference to Current Position

This homing mode regards motor's current position as reference origin. Coordinates positioning
can be done by triggering homing signal without operating the motor.
There is one thing worth noticing when homing in PR mode. When finding the reference point,
motor will decelerate to stop at somewhere close to the reference point because of the inertia.
ASDA-A2 will not request the motor to move to the exact reference origin automatically. Users
may use another PR command to request the motor to move to the origin or to any position in the
coordinate system. Now, the coordinate system has been built, no matter where the motor stops,
the servo will know its stop position on the coordinates. In this case, whether motor stops at the
origin or not, part of the operation such as issuing absolute commands will not be influenced. On
the other hand, when it comes to relative commands or E-CAM applications, the motor has to be
moved to a fixed reference position such as 0 on the coordinates because this type of command
will directly regard motor's stop position as start position.
Please refer to Figure 1.26, if 0 is the homing origin, when motor finds the origin and stops, it will
stop at coordinate position -523. If motor needs to move back to the absolute 0 on the
coordinates, calling PR#1 after homing is required and its absolute position has to be 0.
If motor has to move to any position after homing, this method can be used. For example, motor
has to move to position 44356, users may use the setting of calling one PR path after homing
and regard 44356 as the target position.
1-20
(P5-04.X=8)
Figure 1.25 Regarding Current Position as Home Position
ASDA Series Application Note
March, 2015