Mitsubishi Electric MELSERVO-J4 Instruction Manual page 73

1. TROUBLESHOOTING FOR SERVO AMPLIFIER (DRIVE UNIT)
Alarm No.: 68 Name: STO diagnosis error
Alarm content
Detail
Detail name
No.
68.1 Mismatched (1) STO1 and STO2 are
STO signal
error
(2) The input states of
(3) The setting of [Pr. PF18
(4) The STO circuit is
(5) Something near the
An error of STO input signal was detected.
Cause
Check if the STO1
not inputted correctly. and STO2 of CN8
connector are wired
correctly.
Check the on/off
STO1 and STO2 are states of STO1 and
different. STO2.
Set a longer time in
STO diagnosis error the parameter, and
detection time] ([Pr. then check the
PX43] for when the J3 repeatability.
extension function is
used) is incorrect.
Replace the servo
malfunctioning. amplifier, and then
check the
repeatability.
Check the noise,
device caused it. ambient temperature,
etc.
Check method Check result
It is not wired
correctly.
It is wired correctly.
The on/off states of
STO1 and STO2 are
different.
The on/off states of
STO1 and STO2 are
the same.
It is not repeatable.
It is repeatable.
It is not repeatable.
It is repeatable.
It has a failure.
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Action Target
Wire it correctly. [A]
[B]
[WB]
Check (2).
[GF]
Set STO1 and STO2
to the same input
states.
Check (3).
Review the
parameter setting.
Check (4).
Replace the servo
amplifier.
Check (5).
Take
countermeasures
against its cause.