3 overtravel, Caution, 1) signal setting – Yaskawa Sigma-5 User Manual: Design and Maintenance - Rotary Motors - Analog Voltage and Pulse Train Reference User Manual

Page 120

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5 Operation

5.2.3 Overtravel

5-6

5.2.3 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.

(1) Signal Setting

Rotation in the opposite direction is possible during overtravel by inputting the reference.

CAUTION

• 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.

43

CN1

42

P-OT

N-OT

Limit

switch

Servomotor

SERVOPACK

Limit

switch

Forward direction

45

Type

Name

Connector

Pin Number

Setting

Meaning

Input

P-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 errors
are 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.

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