Mitsubishi Electric MELSERVO MR-J4-B-RJ Series, Instruction Manual

Page: 131 / 174

1. TROUBLESHOOTING FOR SERVO AMPLIFIER (DRIVE UNIT)
1 - 124
Description Possible cause Check result Action Target
Home position deviates at
home position return. 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. Check if a fixed amount (in
one revolution) deviates. Adjust the dog position. [A]
[B]
[WB]
[RJ010]
[GF]
The in-position range is too
large. Check the setting of the in-
position range in [Pr. PA10]. Set a narrower in-position
range.
The proximity dog switch is
failure. Or mounting
proximity dog switch is
incomplete. Check if the proximity dog
signal is inputted correctly. Repair or replace the
proximity dog switch. Adjust
the mounting of the proximity
dog switch.
The program on the
controller side is incorrect. Check the program on the
controller side such as home
position address settings or
sequence programs. Review the programs on the
controller side.
The position deviates during
operation after home position
return.
The position command and
actual machine position are
different. 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. Review the position command
and electronic gear setting.
[A]
[B]
[WB]
[RJ010]
[GF]
The position command and
actual machine position are
different. 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. Review the position
command and electronic
gear setting.
An alarm or warning is
occurring. Check if an alarm or warning
is occurring. Check the content of the
alarm/warning and remove
its cause.
The servo gain is low. Or the
response of auto tuning is
low. Check if the trouble is solved
by increasing auto tuning
response ([Pr. PA09]). Adjust gains.
The reduction ratio is not
calculated correctly for the
geared servo motor. 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]) Review the calculation of the
reduction ratio.
The in-position range is too
large. Check the setting of the in-
position range in [Pr. PA10]. Set a narrower in-position
range.
The command pulses were
miscounted due to noise.
Check that the command
value of the controller and
the number of cumulative
command pulses are
matched. Please take
countermeasures against
noise for the command
cable.
Review the shield procedure
of the command cable.
[A]
The cable for a command is
connected loosely or
disconnected.
Check that the command
value of the controller and
the number of cumulative
command pulses are
matched.
Repair the cable for a
command.