Mitsubishi Electric MELSERVO-J4 Series Instruction Manual page 164

Method -6 and -38 (dog type rear end reference home position return)
This home position return type depends on the timing of reading DOG (Proximity dog) that has detected the
rear end of the proximity dog. Therefore, when the creep speed is set to 100 r/min and a home position return
is performed, the home position has an error calculated by the following expression.
 (Encoder resolution)  100/65536 [pulse]
The higher the creep speed, the greater the error of the home position.
The following figure shows the operation of Homing method -6. The operation direction of Homing method -38 is opposite to
that of Homing method -6.
Statusword bit 10
Target reached
Statusword bit 12
Homing attained
Forward
rotation
Servo motor speed
Reverse
rotation
DOG (Proximity dog)
Controlword bit 4
Homing operation start
*1 After the front end of the proximity dog is detected, if the rear end of the proximity dog is detected without reaching the creep speed, [AL.
90] occurs. Check the length of the proximity dog or check the home position return speed and creep speed.
• When a home position return is started from the proximity dog
Servo motor speed 0 r/min
Reverse
rotation
After retracting to before proximity dog,
the home position return starts from here.
• When the movement is returned at the stroke end
Forward
rotation
Servo motor speed
0 r/min
Reverse
rotation
The home position return starts from here.
*1 This is not available with the software limit.
4 STARTUP
162
4.6 Home position return mode
ON
OFF
ON
OFF
Acceleration time
constant
Home position return speed
0 r/min
3 ms or shorter
ON
OFF
ON
OFF
Home position
return direction
Proximity dog
Home position
return direction
Proximity dog
Home position return start position
Travel distance after proximity dog
Deceleration time
constant
Home position shift distance
*1 Proximity dog
Home position return start position
+
Creep speed
Home position return
position data
*1
Stroke end