Mitsubishi Electric MR-JE-C, Instruction Manual

Page: 233 / 312

12. WHEN USING WITH A GENERAL-PURPOSE INTERFACE
12 - 18
12.4 Homing mode
12.4.1 Outline of homing
A homing is performed to match the command coordinates with the machine coordinates. Under the
incremental method, each power-on of the input power supply requires the home position return.
Contrastingly, in the absolute position detection system, once you have performed the home position return
at machine installation, the current position will be retained even if the power supply is shut off. Therefore,
the home position return is unnecessary when the power supply is switched on again.
This servo amplifier has the homing types shown in this section. Select the optimum method according to the
machine components and applications.
This servo amplifier has the homing automatic retract function, which automatically moves the machine back
to the proper position to perform homing when the machine stops beyond or on a proximity dog. The servo
motor does not need to be rotated manually with JOG operation or by other means.
(1) Homing types
Select the optimum homing according to the machine type or others.
Setting value Home position return types Rotation direction Description
-1
Dog type (rear end detection
Z-phase reference)/
torque limit changing dog type
(front end detection Z-phase
reference)
Forward rotation
Deceleration starts at the front end of the proximity dog. After
the rear end is passed, the position specified by the first Z-
phase signal, or the position of the first Z-phase signal shifted
by the specified home position shift distance is used as the
home position.
In the indexer method, deceleration starts at the front end of the
proximity dog, and then the first Z-phase signal at which a
deceleration to a stop is possible or the position of the Z-phase
signal shifted by the specified home position shift distance is
used as the home position. The torque limit values by [Pr. PA11
Forward rotation torque limit] and [Pr. PA12 Reverse rotation
torque limit] are enabled when performing a homing. The torque
limit value by [Pr. PC35 Internal torque limit 2] is enabled while
the servo motor is stopped.
-33 Reverse rotation
-2
Count type
(Front end detection,
Z-phase reference)
Forward rotation
At the front end of the proximity dog, deceleration starts. After
the front end is passed, the position specified by the first Z-
phase signal after the set distance or the position of the Z-
phase signal shifted by the set home position shift distance is
set as a home position. If the stroke end is detected during
home position return, the travel direction is reversed.
-34 Reverse rotation
-3
Data set type homing/torque
limit changing data set type
The current position is set as the home position.
In the indexer method, the current position is set as the home
position. The torque limit value becomes "0" when switched to
the homing mode.
-4
Stopper type
(Stopper position reference)
Forward rotation
A workpiece is pressed against a mechanical stopper, and the
position where it is stopped is set as the home position. If the
stroke end is detected during home position return, [AL. 90
Home position return incomplete warning] occurs.
-36 Reverse rotation
-5
Home position ignorance
(servo-on position as home
position)
The position where the servo is switched on is used as the
home position.
-6
Dog type
(Rear end detection,
rear end reference)
Forward rotation
Deceleration starts from the front end of the proximity dog. After
the rear end is passed, the position is shifted by the travel
distance after proximity dog and the home position shift
distance. The position after the shifts is set as the home
position. If the stroke end is detected during home position
return, the travel direction is reversed.
-38 Reverse rotation
-7
Count type
(Front end detection, front
end reference)
Forward rotation
Deceleration starts from the front end of the proximity dog. The
position is shifted by the travel distance after proximity dog and
the home position shift distance. The position after the shifts is
set as the home position. If the stroke end is detected during
home position return, the travel direction is reversed.
-39 Reverse rotation