Yaskawa Sigma-5 User Manual: Design and Maintenance - Rotary Motors - MECHATROLINK-II Communications Reference - Manual (Page 314)

9.1 Alarm Displays
9-17
9
Trou
blesh
ooting
A.C90:
Encoder Communica-
tions Error
Contact fault of connector or
incorrect wiring for encoder
cable.
Check the connector contact status
for encoder cable. Re-insert the connector and confirm
that the encoder is correctly wired.
Cable disconnection for encoder
cable or short-circuit.
Or, incorrect cable impedance.
Check the encoder cable.
Use the cable with the specified rat-
ing.
Corrosion caused by improper
temperature, humidity, or gas,
short-circuit caused by intrusion
of water drops or cutting oil, or
connector contact fault caused by
vibration.
Check the operating environment.
Improve the operating environmen-
tal conditions, and replace the cable.
If the alarm still occurs, replace the
SERVOPACK.
Malfunction caused by noise
interference.
−
Correct the wiring around the
encoder by separating the encoder
cable from the servomotor main cir-
cuit cable or by checking the
grounding and other wiring.
A SERVOPACK fault occurred. −
Connect the servomotor to another
SERVOPACK, and turn ON the
control power. If no alarm occurs,
the SERVOPACK may be faulty.
Replace the SERVOPACK.
A.C91:
Encoder Communica-
tions Position Data Er-
ror
Noise interference occurred on
the I/O signal line because the
encoder cable is bent and the
sheath is damaged.
Check the encoder cable and con-
nector. Confirm that there is no problem
with the cable layout.
The encoder cable is bundled
with a high-current line or near a
high-current line.
Check the cable layout for encoder
cable. Confirm that there is no surge volt-
age on the cable.
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 the encoder FG.
A.C92:
Encoder Communica-
tions 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. −
Turn the power supply OFF and
then ON again. If the alarm still
occurs, the servomotor may be
faulty. Replace the servomotor.
A SERVOPACK fault occurred. −
Turn the power supply OFF and
then ON again. If the alarm still
occurs, the SERVOPACK may be
faulty. Replace the SERVOPACK.
A.CA0:
Encoder Parameter
Error
An encoder fault occurred. −
Turn the power supply OFF and
then ON again. If the alarm still
occurs, the servomotor may be
faulty. Replace the servomotor.
A SERVOPACK fault occurred. −
Turn the power supply OFF and
then ON again. If the alarm still
occurs, the SERVOPACK may be
faulty. Replace the SERVOPACK.
(cont’d)
Alarm Number:
Alarm Name
(Alarm Description)
Cause Investigative Actions Corrective Actions