Mitsubishi Electric MELSERVO-J4 Instruction Manual page 100

1. TROUBLESHOOTING FOR SERVO AMPLIFIER (DRIVE UNIT)
If [AL. E6], [AL. E7], [AL. E9], [AL. EA], or [AL. EB] occurs, the amplifier will be the servo-off status. If any
other warning occurs, operation can be continued but an alarm may take place or proper operation may not
be performed.
Remove the cause of warning according to this section. Use MR Configurator2 to refer to the cause of
warning occurrence.
Alarm No.: 90 Name: Home position return incomplete warning
Alarm content
Detail
Detail name
No.
90.1 Home position (1) An automatic operation
return
incomplete
(2) A positioning operation
(3) With the indexer
(4) ZP (Home position
A home position return did not complete normally with the positioning function.
Cause
Check if the home
was executed at home position return was
position return not executed (the
incompletion. following devices are
not off.).
[A]: ZP (Home
position return
completion)
[GF]: ZP2 (Home
position return
completion 2)
Check if [AL. 25
was executed without Absolute position
home position setting erased] occurred
with absolute position using alarm history.
after [AL. 25 Absolute
position erased]
occurred.
Check if [AL. 90.1]
method, [AL. E3 occurred
Absolute position simultaneously with
counter warning] start of the positioning
occurred simultaneously operation.
with the alarm.
Check if ZP (Home
return completion) position return
turned off after the completion) is off.
home position return
was executed.
Check method Check result
A home position
return was not
executed.
A home position
return was executed.
[AL. 25 Absolute
position erased]
occurred.
[AL. 25 Absolute
position erased] did
not occur.
[AL. 90.1] did not
occur simultaneously
with start of the
positioning operation
but occurred during
positioning
operation.
[AL. 90.1] occurred
simultaneously with
start of the
positioning
operation.
ZP (Home position
return completion) is
off.
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Action Target
Execute a home [A]
position return. [GF]
Check (2).
Check the battery
voltage and battery
cable if they have a
failure and execute
a home position
return after remove
the failure.
Check (3).
Remove the cause
of [AL. E3], and
perform home
position return.
(Check it with the
check method for
[AL. E3].)
Check (4).
Check the conditions [A]
if ZP (Home position
return completion)
can be off. (Refer to
section 2.3 of "MR-
J4-_A_-RJ Servo
Amplifier Instruction
Manual (Positioning
Mode)")