YASKAWA S-V Series User Manual page 197

Problem Probable Cause
Noise interference because the lin-
ear scale connection cables are
damaged
Excessive noise to the linear scale
connection cables.
FG electrical potential varies by
influence of such machines on the
linear servomotor side as welders.
Abnormal Noise
from Linear
Servomotor
SERVOPACK pulse counting error
due to noise
(cont'd)
Excessive vibration and shock to
the serial converter unit
A serial converter unit fault
occurred.
A linear scale fault occurred.
Unbalanced servo gains
Speed loop gain value (Pn100) is
too high.
Linear
Servomotor
Position loop gain value (Pn102) is
Vibrates at about
too high.
200 to 400 Hz
Incorrect speed loop integral time
constant (Pn101) setting
Incorrect mass ratio (Pn103) setting
Unbalanced servo gains
Speed loop gain value (Pn100) is
too high.
Position loop gain value (Pn102) is
too high.
High
Speed
Overshoot on Incorrect speed loop integral time
Starting and constant (Pn101) setting
Stopping
Incorrect mass ratio (Pn103) setting
The force reference is saturated.
The force limit (Pn483, Pn484) is
set to the initial value.
9.3 Troubleshooting Malfunction Based on Operation and Conditions
Investigative Actions
Check the linear scale connection
cables to see if they are not dam-
aged or bent.
Check if the linear scale connection
cables are not bundled with high-
current line or not near the high-cur-
rent line.
Check if the machine is correctly
grounded.
Check if there is noise interference
on the I/O signal cable from the
serial converter unit.
Check if vibration from the machine
occurred or serial converter unit
installation is incorrect.
(Mounting surface accuracy, or fix-
ing.)
−
−
Check to see if the servo gains have
been correctly adjusted.
Check the speed loop gain value
(Pn100).
Factory setting: Kv = 40.0 Hz
Check the position loop gain value
(Pn102).
Factory setting: Kp = 40.0/s
Check the speed loop integral time
constant (Pn101) setting.
Factory setting: Ti = 20.0 ms
Check the mass ratio (Pn103) set-
ting.
Check to see if the servo gains have
been correctly adjusted.
Check the speed loop gain value
(Pn100).
Factory setting: Kv = 40.0 Hz
Check the position loop gain value
(Pn102).
Factory setting: Kp = 40.0/s
Check the speed loop integral time
constant (Pn101) setting.
Factory setting: Ti = 20.0 ms
Check the mass ratio (Pn103) set-
ting.
Check the force reference wave-
form.
Initial value of force limit:
Pn483 = 30%
Pn484 = 30%
(cont'd)
Corrective Actions
Replace the linear scale connection
cables, and reconsider the layout of
the linear scale connection cables.
Modify the cable layout so that no
surge from high-current line is
applied to the linear scale connec-
tion cables.
Ground the machine separately
from linear scale side FG.
Take measure against noise for the
serial converter unit wiring.
Reduce vibration from the machine,
or correct the serial converter unit
installation.
Replace the serial converter unit.
Replace the linear scale.
Execute the advanced autotuning.
Reduce the speed loop gain
(Pn100).
Reduce the position loop gain
(Pn102).
Correct the speed loop integral time
constant (Pn101) setting.
Correct the mass ratio (Pn103) set-
ting.
Execute the advanced autotuning.
Reduce the speed loop gain
(Pn100).
Reduce the position loop gain
(Pn102).
Correct the speed loop integral time
constant (Pn101) setting.
Correct the mass ratio (Pn103) set-
ting.
Use the mode switch function.
Set Pn483 and Pn484 (Force Limit)
to an appropriate value.
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