Mitsubishi Electronics MR-J2S- CL User Manual
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4. OPERATION
4.4.2 Dog type home position return
A home position return method using a proximity dog. With deceleration started at the front end of the
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.
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.
(1) Signals, parameters
Set the input signals, parameters and program as follows:
Item
Device/Parameter used
Description
Manual home position return
mode selection
mode selection
Automatic/manual selection (MD0)
MD0 is switched on.
Dog type home position return
Parameter No.8
0 :Dog type home position return is
selected.
Home position return direction
Parameter No.8
Refer to Section 4.4.1 (2) in this section
and choose home position return
direction.
and choose home position return
direction.
Dog input polarity
Parameter No.8
Refer to Section 4.4.1 (2) in this section
and choose dog input polarity.
and choose dog input polarity.
Home position return speed
Parameter No.9
Set speed until detection of dog.
Creep speed
Parameter No.10
Set speed after detection of dog.
Home position shift distance
Parameter No.11
Set when shifting the home position
starting at the first Z-phase signal after
passage of proximity dog rear end.
starting at the first Z-phase signal after
passage of proximity dog rear end.
Home position return
acceleration/deceleration time
constants
acceleration/deceleration time
constants
Parameter No.41
Use the acceleration/deceleration time
constants set in parameter No. 41.
constants set in parameter No. 41.
Home position return position
data
data
Parameter No.42
Used to set the current position on
completion of home position return.
completion of home position return.
Program
Select the program including the "ZRT"
command that executes a home position
return.
command that executes a home position
return.
(2) Length of proximity dog
To ensure that the Z-phase signal of the servo motor is generated during detection of the proximity
dog (DOG), the proximity dog should have the length which satisfies formulas (4.2) and (4.3):
dog (DOG), the proximity dog should have the length which satisfies formulas (4.2) and (4.3):
L
1
60
V
2
td .............................................................................. (4.2)
L
1
: Proximity dog length [mm]
V
: Home position return speed [mm/min]
td : Deceleration time [s]
L
2
2
S.................................................................................... (4.3)
L
2
: Proximity dog length [mm]
S : Moving distance per servo motor revolution [mm]