Mitsubishi Electric MELSERVO-J4 series, Instruction Manual

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16 FULLY CLOSED LOOP SYSTEM
16.3 Operation and functions
Home position return
General instruction
Home position return is all performed according to the load-side encoder feedback data, independently of the load-side
encoder type. It is irrelevant to the Z-phase position of the servo motor encoder. In the case of a home position return using a
dog signal, the home position (reference mark) must be passed through when an incremental type linear encoder is used, or
the Z-phase be passed through when a rotary encoder is used, during a period from a home position return start until the dog
signal turns off.
Load-side encoder types and home position return methods
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About proximity dog type home position return using absolute type linear encoder
When an absolute type linear encoder is used, the home position reference position is the position per servo motor revolution
to the linear encoder home position (absolute position data = 0).
In the case of a proximity dog type home position return, the nearest position after proximity dog off is the home position.
The linear encoder home position may be set in any position.
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About proximity dog type home position return using incremental linear encoder
• When the linear encoder home position (reference mark) exists in the home position return direction
When an incremental linear encoder is used, the home position is the position per servo motor revolution to the linear encoder
home position (reference mark) passed through first after a home position return start.
In the case of a dog type home position return, after the proximity dog signal rear end is detected, the nearest home position
reference position shifted by the home position shift distance is used as the home position.
Set one linear encoder home position in the full stroke, and set it in the proximity dog signal detection position.
*1 Home position shift distance can be changed with [Pr. PT07] and [Pr. PT69].
Linear encoder home position Home position
Home position return speed
Creep speed
Home position return direction
ON
OFF Proximity dog
signal
Servo motor
speed
Reference home
position
Machine position
0 r/min
Equivalent to one servo motor revolution
Linear encoder home position Home position
Home position return speed
Creep speed
Home position return direction
ON
OFF
Proximity dog
signal
Servo motor
speed
Reference home
position
Machine position
0 r/min
Equivalent to one servo motor revolution
Equivalent to servo motor "n" times ro
Home position shift distance *1
Home position shift distance