3.3 FT82 SERVOPACK with MECHATROLINK-III Communications References
3.3.7 Troubleshooting Based on the Operation and Conditions of the Servomotor
3-140
Abnormal
Noise from
Servomotor
Noise interference occurred
because the Encoder Cable
is too long.
Check the length of the
Encoder Cable.
Rotary Servomotors:
The Encoder Cable
length must be 50 m
max.
–
Noise interference occurred
because the Encoder Cable
is damaged.
Check the Encoder Cable
to see if it is pinched or
the sheath is damaged.
Replace the Encoder
Cable and correct the
cable installation envi-
ronment.
–
The Encoder Cable was sub-
jected to excessive noise
interference.
Check to see if the
Encoder Cable is bundled
with a high-current line or
installed near a high-cur-
rent line.
Correct the cable lay-
out so that no surge is
applied by high-current
lines.
–
There is variation in the FG
potential because of the
influence of machines on the
Servomotor side, such as a
welder.
Check to see if the
machines are correctly
grounded.
Properly ground the
machines to separate
them from the FG of
the encoder.
–
There is a SERVOPACK
pulse counting error due to
noise.
Check to see if there is
noise interference on the
signal line from the
encoder.
Implement counter-
measures against noise
for the encoder wiring.
–
The encoder was subjected
to excessive vibration or
shock.
Check to see if vibration
from the machine
occurred. Check the Ser-
vomotor installation
(mounting surface preci-
sion, securing state, and
alignment).
Reduce machine vibra-
tion. Improve the
mounting conditions of
the Servomotor.
–
A failure occurred in the
encoder.
–
Replace the Servomo-
tor.
–
Servomotor
Vibrates at
Frequency
of Approx.
200 to 400
Hz.
The servo gains are not bal-
anced.
Check to see if the servo
gains have been cor-
rectly tuned.
Perform autotuning
without a host refer-
ence.
*
The setting of Pn100 (Speed
Loop Gain) is too high.
Check the setting of
Pn100.
The default setting is Kv =
40.0 Hz.
Set Pn100 to an appro-
priate value.
–
The setting of Pn102 (Posi-
tion Loop Gain) is too high.
Check the setting of
Pn102.
The default setting is Kp
= 40.0/s.
Set Pn102 to an appro-
priate value.
–
The setting of Pn101 (Speed
Loop Integral Time Con-
stant) is not appropriate.
Check the setting of
Pn101.
The default setting is Ti =
20.0 ms.
Set Pn101 to an appro-
priate value.
–
The setting of Pn103
(Moment of Inertia Ratio or
Mass Ratio) is not appropri-
ate.
Check the setting of
Pn103.
Set Pn103 to an appro-
priate value.
–
Continued on next page.
Continued from previous page.
Problem
Possible Cause
Confirmation
Correction
Reference