10 Maintenance, Inspections, and Troubleshooting
10.2.2 Troubleshooting of Alarms
10-12
A.C92:
Encoder
Communications
Timer Error
Noise interference occurred on
the I/O signal line from the
encoder.
−
Take countermeasures against noise
for the encoder wiring.
Excessive vibration and shocks
were applied to the encoder.
Check the operating environment.
Reduce the machine vibration or
correctly install the servomotor.
An encoder fault occurred.
−
Restart the SERVOPACK. If the
alarm still occurs, the servomotor
may be faulty. Replace the servo-
motor.
A.CA0:
Encoder Parameter
Error
An encoder fault occurred.
−
Restart the SERVOPACK. If the
alarm still occurs, the servomotor
may be faulty. Replace the servo-
motor.
A.Cb0:
Encoder Echoback
Error
The wiring and contact for
encoder cable are incorrect.
Check the wiring.
Correct the wiring.
Noise interference occurred due
to incorrect cable specifications
of encoder cable.
−
Use tinned annealed copper
shielded twisted-pair or screened
unshielded twisted-pair cable with a
core of at least 0.12 mm
2
.
Noise interference occurred
because the wiring distance for
the encoder cable is too long.
−
The wiring distance must be 10 m
max.
The FG potential varies because
of influence from machines on
the servomotor side, such as the
welder.
Check the cable layout for encoder
cable.
Properly ground the machines to
separate from encoder FG.
Excessive vibration and shocks
were applied to the encoder.
Check the operating environment.
Reduce the machine vibration or
correctly install the servomotor.
An encoder fault occurred.
−
Restart the SERVOPACK. If the
alarm still occurs, the servomotor
may be faulty. Replace the servo-
motor.
A.CC0:
Multiturn Limit
Disagreement
The multiturn limit value of the
encoder is different from that of
the SERVOPACK. Or, the multi-
turn limit value of the SERVO-
PACK has been changed.
Check the value of the PnA48 of the
SERVOPACK.
Execute Fn013 at the occurrence of
alarm.
A.d00:
Position Error
Overflow
(Position error exceeded
the value set in the
excessive position error
alarm level (Pn520).)
The servomotor U, V, and W wir-
ings is faulty.
Check the servomotor main circuit
cable connection.
Confirm that there is no contact
fault in the motor wiring or encoder
wiring.
The position reference speed is
too high.
Reduce the reference speed, and
operate the SERVOPACK.
Reduce the position reference speed
or acceleration of position refer-
ence. Or, reconsider the electronic
gear ratio.
The acceleration of the position
reference is too high.
Reduce the reference acceleration,
and operate the SERVOPACK.
Reduce the reference acceleration
of the position reference using a
MECHATROLINK command, or
smooth the acceleration of the posi-
tion reference by selecting the posi-
tion reference filter (ACCFIL)
using a MECHATROLINK com-
mand.
Setting of the excessive position
error alarm level (Pn520) is low
against the operating condition.
Check the alarm level (Pn520) to
see if it is set to an appropriate
value.
Set the Pn520 to proper value.
A SERVOPACK fault occurred.
−
Restart the SERVOPACK. If the
alarm still occurs, the SERVO-
PACK may be faulty. Replace the
SERVOPACK.
(cont’d)
Alarm Number:
Alarm Name
(Alarm Description)
Cause
Investigative Actions
Corrective Actions
