Overtravel - YASKAWA Sigma-V Series User Manual

4.3.2 Overtravel

The overtravel limit function of the multi-winding drive unit forces movable machine parts to stop if they
exceed the allowable range of motion and turn ON a limit switch.
For rotating application such as disc table and conveyor, overtravel function is not necessary. In such a case,
no wiring for overtravel input signals is required.
• Installing limit switches
For machines that move using linear motion, connect limit switches to P-OT and N-OT of CN1 as shown below to
prevent machine damage. To prevent a contact fault or disconnection from causing accidents, make sure that the limit
switches are normally closed.
• Axes to which external force is applied in overtravel
Vertical axes:
Occurrence of overtravel may cause a workpiece to fall, because the /BK signal is on, that is when the brake is
released. Set the parameter (Pn001 = n.1) to bring the servomotor to zero clamp state after stopping to prevent
a workpiece from falling.
Other axes to which external force is applied:
Overtravel will bring about a baseblock state after the servomotor stops, which may cause the servomotor to be
pushed back by the load's external force. To prevent this, set the parameter (Pn001 = n.1) to bring the servo-
motor to zero clamp state after stopping.
For details on how to set the parameter, refer to (3) Servomotor Stopping Method When Overtravel is Used.
(1) Signal Setting
Type Name
P-OT
Input
N-OT
Rotation in the opposite direction is possible during overtravel by inputting the reference.
CAUTION
Servomotor
Limit
switch
Connector
Setting
Pin Number
ON
CN1-42
OFF
ON
CN1-43
OFF
4.3 Basic Functions Settings
Forward direction
SERVOPACK
CN1
Limit
N-OT
switch
43
P-OT
42
Meaning
Forward run allowed.
Normal operation status.
Forward run prohibited. Forward overtravel.
Reverse run allowed. Normal operation status.
Reverse run prohibited. Reverse overtravel.
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