4. HOW TO USE THE POINT TABLE
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4.4.7 Dog type rear end reference home position return
POINT
This home position return method depends on the timing of reading DOG
(Proximity dog) that has detected the rear end of a proximity dog. Therefore,
when a home position return is performed at a creep speed of 100 r/min, the
home position has an error of 200 pulses (for HG series servo motor). The
higher the creep speed, the greater the error of the home position.
Deceleration starts from the front end of a proximity dog. After the rear end is passed, the position is shifted
by the travel distance after proximity dog and the home position shift distance. The position after the shifts is
set as the home position. The home position return is available independently of the Z-phase signal.
Changing the creep speed may change the home position.
(1) Device/parameter
Set input devices and parameters as follows.
Item Device/parameter to be used Setting
Home position return mode
selection
MD0 (Operation mode selection 1) Switch on MD0.
DI0 (Point table No. selection 1) to
DI4 (Point table No. selection 5)
Switch off DI0 to DI4.
Dog type rear end reference
home position return
[Pr. PT04]
_ _ _ 5: Select the dog type (rear end
detection/rear end reference).
Home position return
direction
[Pr. PT04]
Refer to section 4.4.1 (2) to select the home
position return direction.
Dog input polarity [Pr. PT29]
Refer to section 4.4.1 (2) to select the dog
input polarity.
Home position return speed [Pr. PT05]
Set the rotation speed specified until a dog is
detected.
Creep speed [Pr. PT06]
Set the rotation speed specified after a dog is
detected.
Home position shift distance [Pr. PT07]
Set this to shift the home position, which is
specified after the rear end of a proximity dog
is passed.
Travel distance after proximity
dog
[Pr. PT09]
Set the travel distance after the rear end of a
proximity dog is passed.
Acceleration time
constant/deceleration time
constant of home position
return
Point table No. 1
The acceleration/deceleration time constant
of point table No. 1 is used.
Home position return position
data
[Pr. PT08]
Set the current position when the home
position return is complete.