YASKAWA Σ-V Series User Manual page 276

Problem Probable Cause
Noise interference due to incorrect
specifications of cable for connect-
ing serial converter unit.
Noise interference because the
cable for connecting serial con-
verter unit is too long
Noise interference because the
cable for connecting serial con-
verter unit is damaged
Abnormal Noise
Excessive noise to the cable for
from Linear
connecting serial converter unit
Servomotor
(cont'd)
FG electrical potential varies by
influence of such machines on the
linear servomotor side as welders.
SERVOPACK pulse counting error
due to noise
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
8.3 Troubleshooting Malfunction Based on Operation and Conditions of the Linear Servomotor
Investigative Actions
The specifications of cable for con-
necting serial converter unit must
be:
Twisted-pair or twisted-pair
shielded wire with core
2
0.12 mm min. and tinned annealed
copper twisted wire.
Check the length of the cable for
connecting serial converter unit.
Check the cable for connecting
serial converter unit to see if it is not
damaged or bent.
Check if the cable for connecting
serial converter unit is not bundled
with high-current line or not near
the high-current 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.
Corrective Actions
Use the specified cable for connect-
ing serial converter unit.
The length of cable for connecting
serial converter unit must be 20 m
max.
Replace the cable for connecting
serial converter unit, and recon-
sider the layout of the cable for con-
necting serial converter unit.
Modify the cable layout so that no
surge from high-current line is
applied to the cable for connecting
serial converter unit.
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.
8
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