Mitsubishi Electric Melservo-J4 Instruction Manual page 81

Alarm No.: 69 Name: Command error
 The command position exceeded 32 bits (-2147483648 to 2147483647) when the software limit is
Alarm content
activated.
 The command position exceeded 30 bits (-536870912 to 536870911) from the value that was set when
the software limit was activated.
 After the detection of LSP (Forward rotation stroke end) or LSN (Reverse rotation stroke end), the
command position exceeded 30 bits (-536870912 to 536870911) from the detected position.
 After the detection of FLS (Upper stroke limit) or RLS (Lower stroke limit), the command position
exceeded 30 bits (-536870912 to 536870911) from the detected position.
Detail Detail name Cause
No.
69.6 Lower stroke (1) The command position
limit detection - exceeded 30 bits from
Command the detected position
excess error after the detection of
RLS (Lower stroke
limit).
(2) The lower stroke limit
switch is not wired.
Or the switch is
incorrectly positioned.
(3)
device caused it.
(4) The controller is
malfunctioning.
Alarm No.: 70 Name: Load-side encoder initial communication error 1
 An error occurred in the initial communication between the load-side encoder and servo amplifier.
Alarm content
Detail Detail name Cause
No.
70.1 Load-side (1)
encoder initial
communication
- Receive data
error 1
(2)
(3)
(4)
(5)
(6)
70.2 Load-side Check it with the check method for [AL. 70.1].
encoder initial
communication
- Receive data
error 2
Check method
Check the command
position.
Check if the limit switch
is wired correctly.
Or check if the switch is
incorrectly positioned.
Something near the Check the noise, ambient
temperature, etc.
Replace the controller,
and then check the
repeatability.
Check method
A load-side encoder Check if the load-side
cable is malfunctioning. encoder cable is
disconnected or shorted.
When you use an A/B/ Check if the servo
Z-phase differential amplifier (MR-J4-_-RJ) is
output linear encoder, compatible with the A/B/
the servo amplifier is Z-phase differential
not compatible with the output linear encoder.
linear encoder.
When you use an A/B/ Check if the wiring of the
Z-phase differential linear encoder is correct.
output linear encoder, (Check if it is wired to
the connection with the PSEL.)
linear encoder is
incorrect.
The servo amplifier is Replace the servo
malfunctioning. amplifier, and then check
the repeatability.
A load-side encoder is Replace the load-side
malfunctioning. encoder, and then check
the repeatability.
Something near the Check the noise, ambient
device caused it. temperature, vibration,
etc.
Check result
The command position
was set to 30 bits or
more.
It was set correctly.
It has a failure.
It has no failure.
There is a problem in the
surrounding.
There is no problem in
the surrounding.
It is not repeatable.
Check result
It has a failure.
It has no failure.
The servo amplifier is not
compatible with it.
The servo amplifier is
compatible with it.
The wiring is incorrect.
The wiring is correct.
It is not repeatable.
It is repeatable.
It is not repeatable.
It is repeatable.
There is a problem in the
surrounding.
1 TROUBLESHOOTING FOR SERVO AMPLIFIER (DRIVE UNIT)
Action Target
Check operation pattern. [GF]
Check (2).
Take countermeasures
against its cause.
Check (3).
Take countermeasures
against its cause.
Check (4).
Replace the controller.
Action Target
Replace or repair the [A]
cable. [B]
[WB]
Check (2).
[GF]
Use a servo amplifier [A]
which is compatible with [B]
it. [GF]
Check (3).
Wire it correctly.
Check (4).
Replace the servo [A]
amplifier. [B]
[WB]
Check (5).
[GF]
Replace the load-side
encoder.
Check (6).
Take countermeasures
against its cause.
1.4 Remedies for alarms
1
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