14.4 Troubleshooting Based on the Operation and Conditions of the Servomotor
Problem
Abnormal
Noise from
Servomotor
Servomotor
Vibrates at
Frequency
of Approx.
200 to 400
Hz.
14-60
Possible Cause
The encoder was subjected
to excessive vibration or
shock.
A failure occurred in the
encoder.
A failure occurred in the
Serial Converter Unit.
A failure occurred in the linear
encoder.
The servo gains are not bal-
anced.
The setting of Pn100 (Speed
Loop Gain) is too high.
The setting of Pn102 (Posi-
tion Loop Gain) is too high.
The setting of Pn101 (Speed
Loop Integral Time Con-
stant) is not appropriate.
The setting of Pn103
(Moment of Inertia Ratio or
Mass Ratio) is not appropri-
ate.
Confirmation
Turn OFF the power sup-
ply to the servo system.
Check to see if vibration
from the machine
occurred. Check the Ser-
vomotor installation
(mounting surface preci-
sion, securing state, and
alignment).
Check the linear encoder
installation (mounting sur-
face precision and secur-
ing method).
−
−
−
Check to see if the servo
gains have been cor-
rectly tuned.
Check the setting of
Pn100.
The default setting is Kv =
40.0 Hz.
Check the setting of
Pn102.
The default setting is Kp
= 40.0/s.
Check the setting of
Pn101.
The default setting is Ti =
20.0 ms.
Check the setting of
Pn103.
Continued from previous page.
Correction
Reference
Reduce machine vibra-
tion. Improve the
−
mounting state of the
Servomotor or linear
encoder.
Turn OFF the power
supply to the servo
−
system.
Replace the Servomo-
tor.
Turn OFF the power
supply to the servo
−
system.
Replace the Serial Con-
verter Unit.
Turn OFF the power
supply to the servo
−
system.
Replace the linear
encoder.
Perform autotuning
without a host refer-
page 8-23
ence.
Set Pn100 to an appro-
−
priate value.
Set Pn102 to an appro-
−
priate value.
Set Pn101 to an appro-
−
priate value.
Set Pn103 to an appro-
−
priate value.
Continued on next page.