Overtravel - YASKAWA E-V-MD Series User Manual

7.3.2 Overtravel

The overtravel limit function 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
Setting
Forward run allowed.
ON
Normal operation status.
OFF Forward run prohibited. Forward overtravel.
ON Reverse run allowed. Normal operation status.
OFF Reverse run prohibited. Reverse overtravel.
7.3 Basic Functions Settings
Forward direction
SERVOPACK
Limit CN1
N-OT
switch
8
P-OT
3
Meaning
7
7-5