7. POSITIONING CONTROL
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7.21.2
Zeroing by the proximity dog method
(1) Proximity dog method
Using the proximity dog method, the home position is the first zero point after
the proximity dog turns OFF.
(2) Zeroing by the proximity dog method
The zeroing operation using the proximity dog method is shown in Fig. 7.31.
ON
OFF
Zeroing
start
Zeroing speed
Creep speed
Zero point
Zeroing direction
The travel value in this range is stored
in the monitoring register: Travel value
after proximity dog turns ON.
Proximity
dog
V
t
A deceleration stop occurs after
the proximity dog turns OFF.
Positioning carried out from this
position to the zero point.
The distance to the zero point is
determined from the servo data.
The travel value in this range is stored
in the monitoring register: Zeroing
second travel value.
Fig. 7.31 Operation of Zeroing by the Proximity Dog Method
(3) Running zeroing
To run zeroing, use the servo program described in Section 7.21.5.
(4) Cautions
Take note of the following points during zeroing by the proximity dog method.
(a) Keep the proximity dog ON during deceleration from the zeroing speed to
the creep speed.
A deceleration stop occurs if the proximity dog turns OFF before
deceleration to the creep speed, and the proximity becomes the home
position.
The next zero point becomes the home position.
A zero point missed during the deceleration stop
the proximity dog turns OFF.
ON
OFF
Zeroing speed
Set creep speed
Zero point
Proximity
dog
after
The zero point in this range does not
becomes the home position
