Mitsubishi Melservo-J2-Super series Instruction Manual page 65

4. OPERATION AND FUNCTIONS
[Precautions]
Note the following if the system uses the positioning module (QD75M) or VME bus Position Board (MR-MC01)
as a position controller.
The scale home position (reference mark) has some
Scale home position
signal
The signal ON width changes depending on the used linear scale.
Contact the scale manufacturer for details.
The positioning module (QD75M) or VME bus Position Board (MR-MC01) determines the home position
reference position when the scale home position (reference mark) is passed through first after power-on of
the servo amplifier. Therefore, a lag equivalent to the scale home position signal width is produced in the
home position reference position depending on the direction in which the scale home position (reference
mark) is passed through.
Home position
reference position
( Passed through
in direction)
Home position
reference position
( Passed through
in direction)
Scale home position
Therefore, when it is desired to always make a home position return to the same position without a lag
equivalent to the scale home position signal width, a home position return must be performed so that the
scale home position is always passed through in the same direction.
The following indicates a home position return method in which a lag equivalent to the scale home
position signal width is not produced in the positioning module (QD75M) or VME bus Position Board
(MR-MC01).
[Home position return method in which lag equivalent to scale home position signal width is not produced]
(a) Move the linear servo motor to the position where the stroke end signal on the side opposite to the
home position return direction turns on.
Machine position
(b) Perform the power-on reset of the servo amplifier or reset the controller.
(c) Switch on the servo and make a home position return.
Home position return operation
Proximity dog
signal
Machine position
ON
OFF
Signal ON width
Equivalent to one motor
encoder revolution
Equivalent to one motor
encoder revolution
ON
OFF
Stroke end
Home position return direction
ON
OFF
Stroke end
width in the region where the signal turns on.
Lag equivalent to scale home position signal ON
width is produced.
Signal ON width
Scale home position
Home position return speed
Scale home position
4 - 10
Home position
Creep speed
Home position