Mitsubishi Electric MELSEC-LD77MS2 User Manual page 890

(2) Troubleshooting when a motor does not rotate
Check items and corrective actions for troubleshooting when a motor does not
rotate are described below.
POINT
The following signals must be ON for the Simple Motion module to operate
(excluding when the "positioning test function" of GX Works2 is used).
• READY signal [X0]
• Servo READY signal
• Upper limit signal and Lower limit signal
The ON status of signals can be checked by the following monitor data.
• Servo READY signal: "
b1).
• Upper limit signal and Lower limit signal: "
Servo status: b0, b1
Md.108
Check item
Is the PLC READY signal turned
ON?
Is the servo amplifier powered ON? Power on the servo amplifier.
Is there an error in the servo
amplifier?
Is the wiring between the Simple
Motion module and servo amplifier
correct?
Is the wiring between the servo
amplifier and motor correct?
Is the wiring of the limit signal
correct?
Is there an error in the Simple
Motion module? (
ERR. LED
flashing)
Isn't the value in "
Md.26
" "1: stopped"?
operation status
Is the value in "
Current feed
Md.20
" changed after positioning
value
control is performed?
Is the cumulative pulse of servo
amplifier changed after positioning
control is performed?
If a motor does not rotate even after the above items are checked, the possible
cause is a hardware failure.
Please consult your local Mitsubishi representative, explaining a detailed
description of the problem.
Servo status (high-order buffer memory address)
Md.108
Md.30
Buffer memory address (high-order)
LD77MS2/LD77MS4
877+100n
Review the program to turn ON the PLC READY signal.
Check the error code of the servo amplifier and take a
corrective action.
Check the wiring between the Simple Motion module
and servo amplifier, and correct it.
Check the wiring between the servo amplifier and motor,
and correct it.
Check the wiring and logic setting of the limit signal, and
correct the wiring.
is on or Check the error code and take a corrective action.
• Review the stop program.
Axis
• Review whether the stop signal (STOP) is not input
erroneously.
Review the start program.
Refer to each servo amplifier instruction manual and
check that the function to suppress the motor rotation
is not working.
16 - 6
Chapter 16 Troubleshooting
" (b0, b1).
External input signal
LD77MS16
2477+100n
n: Axis No.-1
Action
" (b0,