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8. TROUBLESHOOTING
Alarm No.: A.20
Name: Encoder normal communication error 1
Description
Communication error occurred between the encoder and the driver.
Detailed
display
Detailed
Name
Cause
Checking method
Result
Action
20.1
Encoder
transmission
data error
(Driver
receiving
error)
1) Encoder cable is
disconnected.
Check if the encoder
cable is connected
correctly.
Disconnected.
Connect correctly.
Connected
correctly.
Check 2).
2) Encoder cable faulty
Check if the encoder
cable is disconnected
or shorted.
An error is found.
Repair or replace the
cable.
No error.
Check 3).
3) Encoder cable shielding is
faulty
Check the shield
status.
An error is found.
Repair the cable.
No error.
Check 4).
4) Driver fault
Check if the alarm
occurs after replacing
the driver.
Alarm does not
occur.
Replace the driver.
Alarm occurs.
Check 5).
5) Fault in the surrounding
environment
Check the external
noise, the ambient
temperature, etc.
An error is found.
Take the appropriate
measures according to the
cause.
20.5
Encoder
receive data
error 1
(Frame
error)
1) Encoder cable shielding is
faulty
Check the shield
status.
An error is found.
Repair the cable.
No error.
Check 2).
2) Fault in the surrounding
environment
Check the noise, etc.
An error is found.
Take the appropriate
measures according to the
cause.
No error.
Check 3).
3) Encoder fault
Check if the alarm
occurs after replacing
the servo motor.
Alarm does not
occur.
Replace the servo motor.
20.7
Encoder
receive data
error2
(Request
discrepancy)
1) Encoder cable shielding is
faulty
Execute the checking methods mentioned in the alarm display "20.5".
2) Fault in the surrounding
environment
3) Encoder fault
Alarm No.: A.21
Name: Encoder normal communication error 2
Description
Encoder data fault
Detailed
display
Detailed
Name
Cause
Checking method
Result
Action
21.1
Encoder
data error
1) Excessive acceleration is
detected by oscillation,
etc.
Check if the alarm
occurs after the loop
gain is decreased.
Alarm does not
occur.
Operate with the loop gain
decreased.
Alarm occurs.
Check 2).
2) Fault in the surrounding
environment
Check the noise, etc.
An error is found.
Take the appropriate
measures according to the
cause.
No error.
Check 3).
3) Encoder fault
Check if the alarm
occurs after replacing
the servo motor.
Alarm does not
occur.
Replace the servo motor.
21.2
Encoder
data
updating
error
1) Encoder fault
Check if the alarm
occurs after replacing
the servo motor.
Alarm does not
occur.
Replace the servo motor.
21.3
Encoder
waveform
error
1) Encoder fault
Check if the alarm
occurs after replacing
the servo motor.
Alarm does not
occur.
Replace the servo motor.