Mitsubishi Electric MELSERVO-MR-J4 GF Series Instruction Manual page 94

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 of ± (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
Servo motor speed
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. Revise the length of the proximity dog or revise both the home position return speed and creep speed.
*2 The home position shift distance can be changed with [Pr. PT07] and [Pr. PT69].
*3 The travel distance after proximity dog can be changed with [Pr. PT09] and [Pr. PT71].
• When a home position return is started from the proximity dog
Home position return direction
Servo motor speed
Moves back automatically before the proximity dog,
then performs home position return from this position.
• When the movement is returned at the stroke end
Home position return direction
Servo motor speed
Performs home position return from this position.
*1 This is not available with the software limit.
6 SERVO MOTOR DRIVING
92
6.1 Homing mode (hm)
ON
OFF
ON
OFF
Acceleration time
constant
Home position return speed
Forward
rotation
0 r/min
10 ms or shorter
Reverse
rotation
ON
OFF
ON
OFF
0 r/min
Reverse
rotation
Forward
Home position return start position
rotation
0 r/min
Reverse
rotation
Deceleration time
constant
*1
Proximity dog
Proximity dog
Home position return start position
Proximity dog
Travel distance after proximity dog
+
*2
Home position shift distance
Creep speed
Home position return position data
*1
Stroke end
*3