Mitsubishi Electric MELSERVO-J4 MR-J4 TM Instruction Manual page 256

8. TROUBLESHOOTING
8.4 Remedies for alarms
CAUTION
Refer to this section and remedies for alarms of the MR-J4-_A_ and MR-J4-_B_ in "MELSERVO-J4 Servo
Amplifier Instruction Manual (Troubleshooting)" to remove the cause of the alarm. Use MR Configurator2 to
refer to the cause of alarm occurrence.
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.
(4) The STO circuit is
(5) Something near the
When an alarm occurs, eliminate its cause, ensure safety, and deactivate the
alarm to restart operation. Otherwise, it may cause injury.
If [AL. 25 Absolute position erased] occurs, perform the home position setting
again. Otherwise, it may cause an unexpected operation.
As soon as an alarm occurs, make the servo-off status and interrupt the main
circuit power.
POINT
This section explains remedies for alarms exclusively for the MR-J4-_TM_.
Refer to the descriptions of MR-J4-_A_ and MR-J4-_B_ in "MELSERVO-J4
Servo Amplifier Instruction Manual (Troubleshooting)" for remedies for any other
alarms.
When any of the following alarms occurs, do not deactivate the alarm repeatedly
to restart operation. Doing so will cause a malfunction of the servo amplifier and
servo motor. Remove its cause and allow about 30 minutes for cooling before
resuming the operation.
[AL. 30 Regenerative error]
[AL. 46 Servo motor overheat]
[AL. 51 Overload 2]
[AL. 37 Parameter error] is not recorded in the alarm history.
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
PF18 STO diagnosis the parameter, and
error detection time] is then check the
incorrect. repeatability.
Replace the servo
malfunctioning. amplifier, and then
check the
repeatability.
Check the noise,
device caused it. ambient temperature,
etc.
[AL. 45 Main circuit device overheat]
[AL. 50 Overload 1]
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.
8 - 9
Action Target
Wire it correctly. [TM]
Check (2).
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.