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13. POSITIONING MODE
13.6 Home position return mode
13.6.1 Outline of home position return
Home position return is performed to match the command coordinates with the machine coordinates. In the
incremental system, home position return is required every time input power is switched on.
This driver has the home position return methods given in this section. Choose the most appropriate method
for your machine structure and application.
This driver has the home position return automatic return function which executes home position return by
making an automatic return to a proper position if the machine has stopped beyond or on the proximity dog.
Manual motion by JOG operation or the like is not required.
(1) Home position return types
Choose the optimum home position return according to the machine type, etc.
Type
Home position return method
Features
Dog type
With deceleration started at the front end of a
proximity dog, the position where the first Z-
phase signal is given past the rear end of the
dog or a motion has been made over the home
position shift distance starting from the Z-
phase signal is defined as a home position.
(Note)
General home position return method using a
proximity dog.
Repeatability of home position return is excellent.
The machine is less burdened.
Used when the width of the proximity dog can be set
greater than the deceleration distance of the servo
motor.
Count type
With deceleration started at the front end of a
proximity dog, the position where the first Z-
phase signal is given after advancement over
the preset moving distance after the proximity
dog or a motion has been made over the home
position shift distance starting from the Z-
phase signal is defined as a home position.
Home position return method using a proximity dog.
Used when it is desired to minimize the length of the
proximity dog.
Data set type
An arbitrary position is defined as a home
position.
No proximity dog required.
Stopper type
The position where the machine stops when its
part is pressed against a machine stopper is
defined as a home position.
Since the machine part collides with the machine be
fully lowered.
The machine and stopper strength must be
increased.
Home position ignorance
(Servo-on position as
home position)
The position where servo is switched on is
defined as a home position.
Dog type rear end
reference
The position where the axis, which had started
decelerating at the front end of a proximity dog,
has moved the after-proximity dog moving
distance and home position shift distance after
it passed the rear end is defined as a home
position.
The Z-phase signal is not needed.
Count type front end
reference
The position where the axis, which had started
decelerating at the front end of a proximity dog,
has moved the after-proximity dog moving
distance and home position shift distance is
defined as a home position.
The Z-phase signal is not needed.
Dog cradle type
The position where the first Z-phase signal is
issued after detection of the proximity dog front
end is defined as a home position.
Note. The Z-phase signal is a signal recognized in the driver once per servo motor revolution. It cannot be used as an output signal.
