Yaskawa Sigma-5 User Manual: Design and Maintenance - Linear Motors MECHATROLINK-III Communications Reference - Manual (Page 297)

8 Troubleshooting
8-36
Overtravel (OT)
Forward or reverse run prohibited
signal is input.
Check the external power supply
(+24 V) voltage for the input signal.
Correct the external power supply
(+24 V) voltage.
Check if the overtravel limit switch
operates properly.
Correct the overtravel limit switch.
Check if the overtravel limit switch
is wired correctly.
Correct the overtravel limit switch
wiring.
Check the settings for parameters
Pn50A and Pn50B.
Correct the settings for parameters
Pn50A and Pn50B.
Forward or reverse run prohibited
signal malfunctioning.
Check the fluctuation of the exter-
nal power supply (+24 V) voltage
for the input signal.
Stabilize the external power supply
(+24 V) voltage.
Check if the overtravel limit switch
operates correctly.
Correct the overtravel limit switch.
Check if the overtravel limit switch
wiring is correct. (check for dam-
aged cables or loose screws.)
Correct the overtravel limit switch
wiring.
Incorrect forward or reverse run
prohibited signal (P-OT/N-OT)
allocation (parameters Pn50A.3,
Pn50B.0)
Check if the P-OT signal is allo-
cated in Pn50A.3.
If another signal is allocated in
Pn50A.3, allocate P-OT.
Check if the N-OT signal is allo-
cated in Pn50B.0.
If another signal is allocated in
Pn50B.0, allocate N-OT.
Incorrect servomotor stop method
selection
Check the settings for parameters
Pn001.0 and Pn001.1 when the ser-
vomotor power is OFF.
Select a servomotor stop method
other than "coast to stop."
Check the settings for parameters
Pn001.0 and Pn001.1 when in force
control.
Select a servomotor stop method
other than "coast to stop."
Improper Stop
Position by
Overtravel (OT)
Signal
Improper limit switch position and
dog length
−
Install the limit switch at the
appropriate position.
The overtravel limit switch position
is too short for the coasting
distance.
−
Install the overtravel limit switch at
the appropriate position.
(cont’d)
Problem Probable Cause Investigative Actions Corrective Actions