Mitsubishi Electric MELSERVO-J4 Instruction Manual page 84

1. TROUBLESHOOTING FOR SERVO AMPLIFIER (DRIVE UNIT)
Alarm No.: 79 Name: Functional safety unit diagnosis error
Alarm content
Detail
Detail name
No.
79.6 Output device (1) A signal of an output
error
(2) The test pulse time was
(3) Current of the output
(4) The functional safety
(5) Something near the
79.7 Mismatched (1) A mismatch of input
input signal
error
(2) An input mismatch time
(3) The functional safety
(4) Something near the
A diagnosis of the functional safety unit failed.
Cause
Check if the output
device has not been device cable is wired
outputted correctly. correctly. Or check if
the load of the output
device is within the
specifications.
Check the setting of
not set correctly. [Pr. PSD30 Output
device - Test pulse off
time].
Check if the current is
device is excessive. used within
prescribed.
Replace the functional
unit is malfunctioning. safety unit, and then
check the
repeatability.
Check the noise,
device caused it. ambient temperature,
etc.
Check if the input
signal DI_A and DI_B device cable is wired
continued for a fixed correctly.
time ([Pr. PSD18] to [Pr.
PSD23]).
Check the settings of
was not set correctly. [Pr. PSD18 Mismatch
permissible time DI1]
to [Pr. PSD23
Mismatch permissible
time DI6].
Replace the functional
unit is malfunctioning. safety unit, and then
check the
repeatability.
Check the noise,
device caused it. ambient temperature,
etc.
Check method Check result
It has a failure.
It has no failure.
The test pulse width
is longer than the
set value.
The test pulse width
is shorter than the
set value.
Not within
prescribed.
Within prescribed.
It is not repeatable.
It is repeatable.
It has a failure.
It has a failure.
It has no failure.
The mismatched
time is longer than
the set value.
The mismatched
time is shorter than
the set value.
It is not repeatable.
It is repeatable.
It has a failure.
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Action Target
Review the wiring or [A]
load. [B]
[GF]
Check (2).
Set the value longer.
Check (3).
Reduce the output
current.
Check (4).
Replace the
functional safety
unit.
Check (5).
Take
countermeasures
against its cause.
Review the wiring.
Check (2).
Set the value
longer.
Check (3).
Replace the
functional safety
unit.
Check (4).
Take
countermeasures
against its cause.