Home Position Return - Mitsubishi Electric MELSEC iQ-R16MTCPU Programming Manual

5.21

Home Position Return

• Use the home position return at the power supply ON and other times where decision of axis is at the machine home
position is required.
• The home position return data must be set for each axis to execute the home position return. Refer to the following details
of the home position return data. (Page 178 Home Position Return Data)
• The home position return methods that are available are proximity dog method, count method, data set method, dog cradle
method, stopper method, limit switch combined method, scale home position signal detection method, dogless home
position signal reference method, and driver home position return method. Select the optimal home position return method
for the system configuration and applications with reference to the following.
Home position return methods
Proximity dog Proximity dog
method method 1
Proximity dog
method 2
Count method Count method 1
Count method 2
Count method 3
Data set Data set method 1
method
Data set method 2
Data set method 3
Dog cradle method
Stopper Stopper method 1
method
Stopper method 2
Limit switch combined method
Scale home position signal detection
method
Dogless home position signal
reference method
Driver home position return method
*1 The signal in parentheses is required when the home position return retry function is used.
Reference position External signal
Motor zero point DOG
(FLS/RLS)
Command position
Motor zero point

Command position
Motor actual position
Motor zero point DOG
(FLS/RLS)
Motor actual position DOG

Motor zero point FLS (for forward
home position return
direction)/RLS (for
reverse home position
return direction)
DOG
(FLS/RLS)

Position in driver
settings
*1
Applications
• It is used in the system which can surely pass a zero point from
the home position return start to proximity dog ON  OFF.
• When the proximity dog is ON, it cannot be started.
• This method is valid when the stroke range is short and
"proximity dog method 1" cannot be used.
• When the proximity dog is ON, it can be started.
It is used in the system which can surely pass a zero point from
the home position return start to point of travel distance set as
"travel value after proximity dog ON".
This method is used when the proximity dog is near the stroke
end and the stroke range is narrow.
This method is valid when the stroke range is short and "count
method 1" cannot be used.
• It is used in a system where external input signals such as dog
signal are not set in the absolute position system.
• This method is valid for the data set independent of a deviation
counter value.
It is used in a system where external input signals such as dog
signal are not set in the absolute position system.
It is used to perform home position return during servo OFF.
• Home position is zero point of servo motor immediately after
the proximity dog signal ON.
• It is easy to set the position of proximity dog, because the
proximity dog is set near the position made to the home
position.
This method is valid to improve home position accuracy in order
to make the home position for the position which stopped the
machine by the stopper.
It is used in a system where the proximity dog signal cannot be
used and only external limit switch can be used.
• The travel direction is reversed at the proximity dog ON, and
home position is encoder zero point after reversal.
• This method is valid to make the home position for the load
side at the linear motors or direct drive motors use.
• It is used in a system where proximity dog signal cannot be
used and stops at the zero point of servo motor.
• Home position return operation differs by servo amplifier.
The driver performs home position return operation
autonomously according to the settings on the driver-side.
5 POSITIONING CONTROL
5.21 Home Position Return
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