8 - 7
8. TROUBLESHOOTING
Display Name Definition Cause Action
1. Machine struck something. 1. Check operation pattern.
2. Install limit switches.
2. Wrong connection of servo motor.
Servo amplifier's output terminals U,
V, W do not match servo motor's
input terminals U, V, W.
Connect correctly.
3. Servo system is instable and
hunting.
1. Repeat acceleration/deceleration to
execute auto tuning.
2. Change the auto tuning response setting.
3. Set auto tuning to OFF and make gain
adjustment manually.
51 Overload 2 Machine collision or
the like caused max.
For the time of the
alarm occurrence,
refer to the section
10.1.
4. Encoder faulty.
Checking method
When the servo motor shaft is
rotated with the servo off, the
cumulative feedback pulses do not
vary in proportion to the rotary angle
of the shaft but the indication skips
or returns midway.
Change the servo motor.
1. Acceleration/deceleration time
constant is too small.
Increase the acceleration/deceleration time
constant.
2. Torque limit value set with controller
is too small.
Increase the torque limit value.
3. Motor cannot be started due to
torque shortage caused by power
supply voltage drop.
1. Check the power supply capacity.
2. Use servo motor which provides larger
output.
4. Position loop gain 1 (parameter
No.PB08) value is small.
Increase set value and adjust to ensure
proper operation.
5. Servo motor shaft was rotated by
external force.
1. When torque is limited, increase the limit
value.
2. Reduce load.
3. Use servo motor that provides larger
output.
6. Machine struck something. 1. Check operation pattern.
2. Install limit switches.
7. Encoder faulty Change the servo motor.
8. Wrong connection of servo motor.
Servo amplifier's output terminals U,
V, W do not match servo motor's
input terminals U, V, W.
Connect correctly.
52 Error excessive The deviation
between the model
position and the
actual servo motor
position exceeds the
parameter No.PC01
setting value (initial
value: 3 revolutions).
9. SSCNET cable fault Change the SSCNET cable.
10. Optical characteristic of SSCNET
cable deteriorated because vinyl
tape and/or wire sheath, which
contains migrating plasticizer,
adhered to the cable.
Remove the vinyl tape and/or wire sheath,
which contains migrating plasticizer, and
exchange the cable.
8A USB
communication
time-out error
Communication with
MR Configurator in
test operation mode
stopped for longer
than the specified
time.
1. USB cable breakage. Change the USB cable.
1. USB cable fault
(Open cable or short circuit)
Change the USB cable. 8E USB
communication
error
Serial communication
error occurred
between servo
amplifier and
communication
device (e.g. personal
computer).
2. Communication device (e.g.
personal computer) faulty
Change the communication device (e.g.
personal computer).