98
3 BASIC FUNCTION
3.5 Stroke limit function [A]
3.5
Stroke limit function [A]
The stroke limit function is a function that limits the travel distance of servo motors. On a system configuration where the
movable range is limited, wire the stroke limit signal and use this function to prevent machine damage due to a collision.
When the stroke limit signal is detected, a warning regarding the detected signal occurs, and the servo motor stops based on
the stop method described in this section.
When a system configuration without the limited movable range is used and therefore the stroke limit function is not
necessary, set the stroke limit signal to always on.
• The stroke limit signal cannot be used in the torque mode. In the torque mode of the linear servo motor and
the direct drive motor, the stroke limit signal can be used only at the time of magnetic pole detection.
Precautions
• The stroke limit signal is the signal for a normally closed contact. The limit is released when the contact is on (shorted), and
the limit is in progress when the contact is off (open).
• Depending on the stop method setting of the stroke limit and the commands from the controller, the home position may be
erased when the servo motor is stopped by the stroke limit signal being detected during operation. If the home position is
erased, perform homing again.
Setting methods of functions
Refer to the following table, and make the appropriate settings for the system configuration.
When wiring the limit switch to the servo amplifier
Input the output signal of the limit switch (LSP and LSN) to the servo amplifier.
Wire the limit switch installed in CCW or the positive direction to LSP, and wire the limit switch installed in CW or the negative
direction to LSN.
In the initial setting, LSP (Forward rotation stroke end) is assigned to the CN3-43 pin, and LSN (Reverse rotation stroke end)
is assigned to the CN3-44 pin.
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System configuration example
Item
Reference for this section
When wiring the limit switch to the servo amplifier
Page 98 When wiring the limit switch to the servo amplifier
When the movable range is not limited
Page 99 When the movable range is not limited
CN3-44
LSP
LSN
CN3-43
Controller
Servo amplifier
Movable range
Limit switch
Limit switch
Moving
part
CCW or positive direction