4 Operation4.3.2 Overtravel4-64.3.2 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.(2) Overtravel Function SettingParameters Pn50A and Pn50B can be set to enable or disable the overtravel function.If the overtravel function is not used, no wiring for overtravel input signals will be required.A parameter can be used to re-allocate input connector number for the P-OT and N-OT signals. Refer to 3.3.1Input Signal Allocations for details.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:There is a risk of the workpiece falling during the overtravel status because the /BK signal will remain ON (brakerelease). Set the zero clamp status after the servomotor stops (Pn001 = n.1) to prevent the 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.8CN17P-OTN-OTLimitswitchSERVOPACKLimitswitchForward directionServomotorType Name ConnectorPin Number Setting MeaningInputP-OT CN1-7 ON Forward run allowed.Normal operation status.OFF Forward run prohibited. Forward overtravel.N-OT CN1-8 ON Reverse run allowed. Normal operation status.OFF Reverse run prohibited. Reverse overtravel.Parameter Meaning WhenEnabled ClassificationPn50An.1[Factory setting]Inputs the Forward Run Prohibited (P-OT) signal fromCN1-7.After restart Setupn.8 Disables the Forward Run Prohibited (P-OT) signal.Allows constant forward rotation.Pn50Bn.2 [Fac-tory setting]Inputs the Reverse Run Prohibited (N-OT) signal fromCN1-8.n.8 Disables the Reverse Run Prohibited (N-OT) signal.Allows constant reverse rotation.
