Mitsubishi Electric MELSERVO-JN Series Instruction Manual page 21

№ Step of occurrence
3 Input command Servo motor rotates in
pulse. reverse direction.
(Test operation)
(In the position
control mode)
4 Switch on forward Servo motor does not
rotation start (ST1) rotate.
or reverse rotation
start (ST2).
(In the internal
speed control
mode)
5 Switch on forward Servo motor does not
rotation selection rotate.
(RS1) or reverse
rotation selection
(RS2).
(In the internal
torque control
mode)
6 Switch on forward Servo motor does not
rotation start (ST1) rotate.
or reverse rotation
start (ST2).
(In the positioning
mode)
7 Gain adjustment Rotation ripples (speed
(In the position fluctuations) are large at
control mode) low speed.
(In the internal
speed control
mode)
(In the positioning
mode)
Large load inertia
moment causes the
servo motor shaft to
oscillate side to side.
8 Cyclic operation Position shift occurs.
(In the position
control mode)
Fault
Check the cumulative command
pulses on the status display or on
MR Configurator.
Check the set value of parameter
No.PA14 (rotation direction
selection).
Check the ON/OFF status of the
input signal on the external I/O
signal display (refer to section
5.8).
Check the internal speed
commands 0 to 7 (parameters No.
PC05 to PC08 and PC31 to
PC34).
Check the forward torque limit
(parameter No. PA11) or reverse
torque limit (parameter No. PA12).
Check the set value of parameter
No.PC12 (internal torque
command).
Check the ON/OFF status of the
input signal on the external I/O
signal display (refer to section
5.8).
Check the internal speed limits 0
to 7 (parameters No. PC05 to
PC08 and PC31 to PC34).
Check the forward torque limit
(parameter No. PA11) or reverse
torque limit (parameter No. PA12).
Check the ON/OFF status of the
input signal on the external I/O
signal display (refer to section
5.8).
Check the values of position data
and servo motor speed set in the
point table or program.
Check the forward torque limit
(parameter No. PA11) or reverse
torque limit (parameter No. PA12).
Make gain adjustment in the
following procedure.
1. Increase the auto tuning
response level.
2. Repeat acceleration and
deceleration several times to
complete auto tuning.
If the servo motor may be run with
safety, repeat acceleration and
deceleration several times to
complete auto tuning.
Confirm the cumulative command
pulses, the cumulative feedback
pulses and the actual servo motor
position.
Investigation
1. Mistake in wiring to controller.
2. Mistake in setting of parameter
LSP, LSN, ST1 or ST2 is off.
Set value is 0.
Torque limit level is too low as
compared to the load torque.
Internal torque command is too
low as compared to the load
torque.
RS1 or RS2 is off.
Set value is 0.
Set value is 0.
LSP, LSN, ST1 or ST2 is off.
Set value is 0.
Torque limit level is too low as
compared to the load torque.
Gain adjustment fault
Gain adjustment fault
Pulse counting error, etc. due to
noise.
- 12 -
Introduction
Possible cause
No. PA14.
Reference
Section
4.1.12
Section
5.3
Section
5.8
Section
4.3.2
Section
4.1.10
Section
4.3.2
Section
5.8
Section
4.3.2
Section
4.1.10
Section
5.8
Chapter
13
Section
4.1.10
Chapter 6
Chapter 6
(2) in this
section