Mitsubishi Electric Melservo-J3 Series MR-J3-B, Instruction Manual

Page: 682 / 802

16 - 127
16. INDEXER POSITIONING OPERATION
Description Check method Possible cause Action
The servo motor
starts rotating
upon the power-
on of the servo
amplifier, or the
servo motor
starts rotating
upon servo-on. Check if the servo-on is turned
ON. Servo-on has been on at power-on. Check the controller programs.
For a servo motor with an
electromagnetic brake, check the
timing of releasing the
electromagnetic brake. 1. The sequence of releasing the
electromagnetic brake is incorrect.
2. Failure of power supply for the
electromagnetic brake.
1. Check the sequence of releasing the
electromagnetic brake.
2. Check the power supply for the
electromagnetic brake.
Check the servo motor power
cable. The output circuit is open phase. Check the wiring of the servo motor
power cable.
The position
deviates at the
home position
return. A fixed amount (in one revolution)
deviates. (Dog type home position
return) Detection of a zero pulse is near dog off
position (Dog type home position return) Adjust the installation of the proximity
dog.
Check the in-position range
(parameter No.PA10). The in-position range is too large. Set a narrower in-position range.
Check if the proximity dog signal
is inputted correctly. 1. The proximity dog switch is faulty.
2. The installation of the proximity dog is
faulty.
1. Repair or replace the proximity dog
switch.
2. Adjust the mounting of the proximity
dog switch.
Check the installation of the
proximity dog switch. The position of the proximity dog switch
is deviated , or installation of the
proximity dog is faulty. Adjust the installation of the proximity
dog switch.
Check the controller programs. The controller programs are incorrect. Check the controller programs.
The position
deviates during
operation after
the home
position return.
Check the servo alarm and
warning. 1. A servo alarm occurred.
2. The servo motor coasted by the servo
alarm.
Check the the alarm content, and
remove its cause.
The command position and
current position do not match. Forward rotation stroke end (LSP) or
reverse rotation stroke end (LSN) was
turned off.
(A99 occurred.) Check the wiring of forward rotation
stroke end (LSP) and reverse rotation
stroke end (LSN).
"Cumulative feedback pulses ×
feed length multiplication" does
not match the actual machine
position. 1. A mechanical slip occurred.
2. The backlash of the machine part is
large.
Adjust the machine part.
Cumulative feedback pulses does
not match "Cumulative command
pulses × electronic gear setting"
value. Temporary disconnection of the power
supply line Review the wiring.
1. The servo gain is low.
2. The auto tuning response is low.
3. Settling time is slow. Increase the auto tuning response, and
readjust the gain. (Refer to chapter 9.)
1. Forward rotation stroke end (LSP) or
reverse rotation stroke end (LSN) was
turned off. (A99 occurred.)
2. Clear (CR) and reset (RES) were
turned on.
1. Review the wiring and sequence of
each signal.
2. Review the controller programs.
3. If a malfunction may occur due to
much noise, increase the setting
value of input filter setting
(parameter No.PD19).