Mitsubishi Electric MELSERVO-J4 Instruction Manual Trouble Shooting page 25

1. TROUBLESHOOTING
Alarm No.: 20 Name: Encoder normal communication error 1
Alarm content
Detail
Detail name
No.
20.7 Encoder normal Check it with the check method for [AL. 20.1].
communication -
Transmission
data error 3
20.9 Encoder normal
communication -
Receive data
error 4
20.A Encoder normal
communication -
Receive data
error 5
Alarm No.: 21 Name: Encoder normal communication error 2
Alarm content
Detail
Detail name
No.
21.1 Encoder data (1)
error 1
(2) An encoder is
(3) Something near the
21.2 Encoder data (1) An encoder is
update error
(2) Something near the
21.3 Encoder data Check it with the check method for [AL. 21.2].
waveform error
21.4 Encoder non- (1)
signal error
(2) Something near the
21.5 Encoder Check it with the check method for [AL. 21.2].
hardware
error 1
21.6 Encoder
hardware
error 2
21.9 Encoder data Check it with the check method for [AL. 21.1].
error 2
Communication error occurred between encoder and servo amplifier.
Cause
The encoder detected an error signal.
Cause
The encoder detected a Decrease the loop
high speed/acceleration gain, and then check
rate due to an oscillation the repeatability.
or other factors.
Replace the servo
malfunctioning. motor, and then check
the repeatability.
Check the noise,
device caused it. ambient temperature,
vibration, etc.
Replace the servo
malfunctioning. motor, and then check
the repeatability.
Check the noise,
device caused it. ambient temperature,
etc.
A signal of the encoder Check if the encoder
has not been inputted. cable is wired
correctly.
Check the noise,
device caused it. ambient temperature,
etc.
Check method Check result
Check method Check result
It is not repeatable.
It is repeatable.
It is not repeatable.
It is repeatable.
It has a failure.
It is not repeatable.
It is repeatable.
It has a failure.
It has a failure.
It has no failure.
It has a failure.
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Action Target
Action Target
Use the encoder with [A]
low loop gain. [B]
[WB]
Check (2).
[RJ010]
Replace the servo
motor.
Check (3).
Take
countermeasures
against its cause.
Replace the servo
motor.
Check (2).
Take
countermeasures
against its cause.
Review the wiring. [A]
[B]
Check (2).
[WB]
Take
countermeasures
against its cause.