5 Operation5.2.3 Overtravel5-65.2.3 OvertravelThe overtravel limit function forces movable machine parts to stop if they exceed the allowable range ofmotion 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.(1) Signal SettingRotation in the opposite direction is possible during overtravel by inputting the reference.CAUTION• Installing limit switchesFor machines that move using linear motion, connect limit switches to P-OT and N-OT of CN1 as shown below toprevent machine damage. To prevent a contact fault or disconnection from causing accidents, make sure that the limitswitches are normally closed.• Axes to which external force is applied in overtravelVertical axes:Occurrence of overtravel may cause a workpiece to fall, because the /BK signal is on, that is when the brake isreleased. Set the parameter (Pn001 = n.1) to bring the servomotor to zero clamp state after stopping to preventa 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 bepushed 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.43CN142P-OTN-OTLimitswitchServomotor SERVOPACKLimitswitchForward directionType Name ConnectorPin Number Setting MeaningInputP-OT CN1-42 ON Forward run allowed.Normal operation status.OFF Forward run prohibited. Forward overtravel.N-OT CN1-43 ON Reverse run allowed. Normal operation status.OFF Reverse run prohibited. Reverse overtravel.When the servomotor stops due to overtravel during position control, the position errorsare held. A clear signal (CLR) input is required to clear the error pulses.For the clear signal, refer to 5.4.2 Clear Signal Setting.
