Mitsubishi MELDAS MDS-C1 Instruction Manual page 268

Feedback error 1
Alarm No.
With the servo, pulse-type position detector feedback signal error was detected. With the spindle, a
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PLG feedback signal error was detected.
Investigation details
1 Check whether the drive unit
connectors (servo: CN3, spindle:
CN6) or detector connectors are
disconnected.
2 Turn the power OFF, and check the
detector cable connection with a
tester.
3 Connect to another normal axis drive
unit, and check whether the fault is
on the drive unit side or detector side.
4 Check the PLG output waveform.
5 Check if there is any abnormality in
the detector's ambient environment.
(Ex. Ambient temperature, noise,
grounding)
Feedback error 2
Alarm No.
With the servo, an excessive error was detected in the position data for the motor side detector and
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machine side detector. With the spindle, an error was detected in the encoder feedback signal.
Investigation details
1 Check whether the drive unit
connectors or detector connectors
are disconnected.
2 Is the detector cable wired in the
same conduit as the motor's power
cable or are the two cables laid in
parallel near each other?
3 Is the motor FG wire connected only
to the drive unit which drives it?
(Is the motor grounded to one point?) The motor is grounded to one point.
4 Turn the power OFF, and check the
detector cable connection with a
tester. (Is the cable shielded?)
5 Connect to another normal axis drive
unit, and check whether the fault is
on the drive unit side or detector side.
6 Check if there is any abnormality in
the detector's ambient environment.
(Ex. Ambient temperature, noise,
grounding)
6. Troubleshooting
Investigation results
The connector is disconnected (or
loose).
The connector is not disconnected.
There is a connection fault.
The connection is normal.
The alarm is on the drive unit side.
The alarm is on the detector side.
There is a problem.
Normal
No abnormality is found in particular.
An abnormality was found in the
ambient environment.
Investigation results
The connector is disconnected (or
loose).
The connector is not disconnected.
The cables are wired near each
other. (Noise is entering from the
power cable.)
The wires are sufficiently separated.
The motor FG wire is grounded on
the motor side.
There is a connection fault.
The connection is normal.
The alarm is on the drive unit side.
The alarm is on the detector side.
No abnormality is found in particular.
An abnormality was found in the
ambient environment.
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Remedies
Correctly install.
Investigate item 2.
Replace the detector cable.
Investigate item 3.
Replace the drive unit.
Servo : Investigate item 5.
Spindle : Investigate item 4.
Adjust the PLG output waveform.
Investigate item 5.
Replace the detector.
(With the absolute position system,
the zero point must be established.)
Take remedies according to the
causes of the abnormality.
Ex. High temperature:
Check the cooling fan.
Incomplete grounding:
Additionally ground.
Remedies
Correctly install.
Investigate item 2.
Improve the cable wiring.
Investigate item 3.
Connect together on the drive unit
side.
Investigate item 4.
Replace the detector cable.
Investigate item 5.
Replace the drive unit.
Investigate item 6.
Replace the detector.
(With the absolute position system,
the zero point must be established.)
Take remedies according to the
causes of the abnormality.
Ex. High temperature:
Check the cooling fan.
Incomplete grounding:
Additionally ground.
SV SP
SV SP