Mitsubishi Electric MELSERVO-JE, Instruction Manual

Page: 88 / 116

6. SERVO MOTOR DRIVING
6 - 23
(b) Method -2 and -34 (Count type home position return)
POINT
For the count type home position return, after the front end of the proximity dog
is detected, the position is shifted by the distance set in the travel distance after
proximity dog. Then, the first Z-phase is set as the home position. Therefore,
when the on-time of the proximity dog is 10 ms or more, the length of the
proximity dog has no restrictions. Use this home position return type when the
dog type home position return cannot be used because the length of the
proximity dog cannot be reserved or other cases.
The following figure shows the operation of Homing method -2. The operation direction of Homing
method -34 is opposite to that of Homing method -2.
Home position return speed
Creep speed
Proximity dog (Note)
Deceleration time
constant
Home position return
position data
Servo motor speed
Reverse
rotation
0 r/min
Forward
rotation
Statusword bit 10
Target reached
ON
OFF
ON
OFF
Statusword bit 12
Homing attained
ON
OFF
ON
OFF
Controlword bit 4
Homing operation start
ON
OFF
Z-phase
DOG (Proximity dog)
Acceleration time
constant
Travel distance after
proximity dog
Home position
shift distance
10 ms or shorter
Note. After the front end of the proximity dog is detected, if the distance after proximity dog is traveled without reaching the creep speed,
[AL. 90] occurs. Set the travel distance after proximity dog enough for the servo motor to decelerate from the home position return
speed to the creep speed.
Servo motor speed
Reverse
rotation
0 r/min
Home position
return direction
Home position return start position
After retracting to before proximity dog,
the home position return starts from here.
Proximity dog
When a home position return is started from the proximity dog