Mitsubishi Electric MELSERVO-J4 Instruction Manual page 131

1. TROUBLESHOOTING FOR SERVO AMPLIFIER (DRIVE UNIT)
Description
Home position deviates at
home position return.
The position deviates during
operation after home position
return.
Possible cause
For the dog type home
position return, the point
which the dog turns off and
the point which Z-phase
pulse is detected (CR input
position) are too close.
The in-position range is too
large.
The proximity dog switch is
failure. Or mounting
proximity dog switch is
incomplete.
The program on the
controller side is incorrect.
The position command and
actual machine position are
different.
The position command and
actual machine position are
different.
An alarm or warning is
occurring.
The servo gain is low. Or the
response of auto tuning is
low.
The reduction ratio is not
calculated correctly for the
geared servo motor.
The in-position range is too
large.
The command pulses were
miscounted due to noise.
The cable for a command is
connected loosely or
disconnected.
Check result
Check if a fixed amount (in
one revolution) deviates.
Check the setting of the in-
position range in [Pr. PA10].
Check if the proximity dog
signal is inputted correctly.
Check the program on the
controller side such as home
position address settings or
sequence programs.
Check that "cumulative
feedback pulses × travel
distance per pulse" matches
the actual machine position.
Check if "cumulative feedback
pulses × feed length
multiplication" matches the
actual machine position.
Check that "cumulative
feedback pulses × travel
distance per pulse" matches
the actual machine position.
Check if "cumulative feedback
pulses × feed length
multiplication" matches the
actual machine position.
Check if an alarm or warning
is occurring.
Check if the trouble is solved
by increasing auto tuning
response ([Pr. PA09]).
Check the following settings.
[A]:
Number of command input
pulses per revolution ([Pr.
PA05]) or electronic gear
([Pr. PA06] and [Pr. PA07])
[B] [WB] [RJ010]:
Number of pulses per
revolution, travel distance
(setting on the controller
side)
[GF]: Electronic gear ([Pr.
PA06], [Pr. PA07])
Check the setting of the in-
position range in [Pr. PA10].
Check that the command
value of the controller and
the number of cumulative
command pulses are
matched.
Check that the command
value of the controller and
the number of cumulative
command pulses are
matched.
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Action
Adjust the dog position.
Set a narrower in-position
range.
Repair or replace the
proximity dog switch. Adjust
the mounting of the proximity
dog switch.
Review the programs on the
controller side.
Review the position command
and electronic gear setting.
Review the position
command and electronic
gear setting.
Check the content of the
alarm/warning and remove
its cause.
Adjust gains.
Review the calculation of the
reduction ratio.
Set a narrower in-position
range.
Please take
countermeasures against
noise for the command
cable.
Review the shield procedure
of the command cable.
Repair the cable for a
command.
Target
[A]
[B]
[WB]
[RJ010]
[GF]
[A]
[B]
[WB]
[RJ010]
[GF]
[A]