Mitsubishi Electric Melservo-J4 Instruction Manual page 73

Alarm No.: 54 Name: Oscillation detection
 An oscillation of the servo motor was detected.
Alarm content
Detail Detail name Cause
No.
54.1 Oscillation (1) The servo system is
detection error unstable and oscillating.
(2) The resonance
frequency has changed
due to deterioration.
(3) The encoder or linear
encoder is
malfunctioning.
Alarm No.: 56 Name: Forced stop error
 The servo motor does not decelerate normally during forced stop deceleration.
Alarm content
Detail Detail name Cause
No.
56.2 Over speed (1) The forced stop
during forced deceleration time
stop constant is short.
[A]: [Pr. PC51]
[B] [WB] [RJ010] [GF]:
[Pr. PC24]
(2) The torque limit has
been enabled.
(3) The servo system is
unstable and oscillating.
(4) The encoder or linear
encoder is
malfunctioning.
56.3 Estimated (1) The forced stop
distance over deceleration time
during forced constant is short.
stop [A]: [Pr. PC51]
[B] [WB] [RJ010] [GF]:
[Pr. PC24]
(2) The torque limit has
been enabled.
(3) The encoder or linear
encoder is
malfunctioning.
Check method Check result
Check if the servo motor The torque ripple is
is oscillating. Check the vibrating.
torque ripple with MR
Configurator2.
The torque ripple is not
vibrating.
Measure the resonance The resonance
frequency of the frequency of the
equipment and compare equipment is different
it with the setting value of from the filter setting
the machine resonance value.
suppression filter.
The resonance
frequency of the
equipment is the same
as the filter setting value.
Replace the servo motor It is not repeatable.
or linear encoder, and
then check the
repeatability.
Check method Check result
Increase the parameter It is not repeatable.
setting value, and then
check the repeatability.
It is repeatable.
Check if the limiting The limiting torque is in
torque is in progress. progress.
The limiting torque is not
in progress.
Check if the servo motor The torque ripple is
is oscillating. Check the vibrating.
torque ripple with MR
Configurator2.
The torque ripple is not
vibrating.
Replace the servo motor It is not repeatable.
or linear encoder, and
then check the
repeatability.
Increase the parameter It is not repeatable.
setting value, and then
check the repeatability.
It is repeatable.
Check if the limiting The limiting torque is in
torque is in progress. progress.
The limiting torque is not
in progress.
Replace the servo motor It is not repeatable.
or linear encoder, and
then check the
repeatability.
1 TROUBLESHOOTING FOR SERVO AMPLIFIER (DRIVE UNIT)
Action Target
Adjust the servo gain [A]
with the auto tuning. Set [B]
the machine resonance [WB]
suppression filter. [RJ010]
[GF]
Check (2).
Change the setting value
of the machine
resonance suppression
filter.
Check (3).
Replace the servo motor
or linear encoder.
Action Target
Adjust the deceleration [A]
time constant. [B]
[WB]
[RJ010]
Check (2).
[GF]
Review the torque limit
value.
Check (3).
Adjust the servo gain.
Set the machine
resonance suppression
filter.
Check (4).
Replace the servo motor
or linear encoder.
Adjust the deceleration
time constant.
Check (2).
Review the torque limit
value.
Check (3).
Replace the servo motor
or linear encoder.
1.4 Remedies for alarms
1
71