Mitsubishi Electric MELSERVO-JE, Instruction Manual

Page: 92 / 116

6. SERVO MOTOR DRIVING
6 - 27
(f) Method -7 and -39 (count type front end reference home position return)
POINT
This home position return type depends on the timing of reading DOG (Proximity
dog) that has detected the front 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
faster home position return speed sets a larger error in the home position.
The following figure shows the operation of Homing method -7. The operation direction of Homing
method -39 is opposite to that of Homing method -7.
Proximity dog
Home position return speed
Creep speed
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
DOG (Proximity dog)
Acceleration time
constant
Travel distance after proximity dog
+
Home position shift distance
10 ms or shorter
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
Servo motor speed
Reverse
rotation
0 r/min
Forward
rotation
The home position return starts from here.
Home position
return direction
Home position return start position
Proximity dog
Stroke end (Note)
Note. This is not available with the software limit.
When the servo motor returns at the stroke end