Mitsubishi MR-JE-40A - Dog Type Home Position Return

5. HOW TO USE THE PROGRAM
5 - 40
5.4.2 Dog type home position return
This is a home position return method using a proximity dog. Deceleration starts at the front end of the
proximity dog. After the rear end is passed, the position specified by the first Z-phase signal, or the position
of the first Z-phase signal shifted by the specified home position shift distance is used as the home position.
(1) Device/parameter
Set input devices and parameters as follows:
Item Device/parameter to be used Setting
Automatic operation mode of
the program method
MD0 (Operation mode selection 1) Switch on MD0.
Dog type home position
return
[Pr. PT04]
_ _ _ 0: Select dog type (rear end detection Z-
phase reference)
Home position return
direction
[Pr. PT04]
Refer to section 5.4.1 (2) to select the home
position return direction.
Dog input polarity [Pr. PT29]
Refer to section 5.4.1 (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 by the first Z-phase signal after the rear
end of the proximity dog is passed.
Acceleration time constant of
home position return
[Pr. PC30]
The acceleration time constant set for [Pr. PC30]
is used.
Deceleration time constant of
home position return
[Pr. PC31]
The deceleration time constant set for [Pr. PC31]
is used.
Home position return position
data
[Pr. PT08]
Set the current position when the home position
return completed.
Program
DI0 (Program No. selection 1) to
DI3 (Program No. selection 4)
Select a program containing a "ZRT" command,
which performs the home position return.
(2) Length of the proximity dog
To generate the Z-phase signal of the servo motor during the detection of DOG (Proximity dog), set the
length of the proximity dog that satisfies equations (5.1) and (5.2).
L
1
≥
V
60
td
2
·············································································································· (5.1)
L
1
: Length of the proximity dog [mm]
V: Home position return speed [mm/min]
td: Deceleration time [s]
L
2
≥ 2 ∆S ················································································································· (5.2)
L
2
: Length of the proximity dog [mm]
∆S: Travel distance per servo motor revolution [mm]