MITSUBISHI ELECTRIC MR-J2S- CP - Manual (Page 119)

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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.
(1) Signals, parameters
Set the input signals and parameters as follows.
Item Device/Parameter used Description
Automatic/manual selection (MD0) Short MD0-SG (ON).
Point table No. selection 1 (DI0) Open DI0-SG (OFF).
Manual home position return
mode selection
Point table No. selection 2 (DI1) Open DI1-SG (OFF).
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) and choose home
position return direction.
Dog input polarity Parameter No.8
Refer to section 4.4.1 (2) 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.
Home position return
acceleration/deceleration time
constants
Point table No.1
Use the acceleration/deceleration time
constants of point table No.1.
Home position return position
data
Parameter No.42
Use to set the current position on
completion of 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).
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]