Troubleshooting By Symptom - Mitsubishi Electric RD77MS2 User Manual

14.2

Troubleshooting by Symptom

Troubleshooting when a motor does not rotate
Check items and corrective actions for troubleshooting when a motor does not rotate are described below.
Check item
Is the PLC READY signal turned ON?
Is the servo amplifier powered ON?
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 is
on or flashing)
Isn't the value in "[Md.26] Axis operation status" "1:
stopped"?
Is the value in "[Md.20] Current feed value" changed after
positioning 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.
Troubleshooting when a motor does not rotate as intended.
Check items and corrective actions for troubleshooting when a motor does not rotate as intended are described below.
■When a motor rotates only in the opposite direction
Check item
Is the value in "Rotation direction selection/travel
direction selection (PA14)" correct?
■When a motor does not rotate at the set speed
Check item
Does the value in "[Md.28] Axis feedrate"
indicate the set speed?
*1 Speed control mode and continuous operation to torque control mode: "[Md.122] Speed during command"
■When the set position is not reached
Check item
Does the value in "[Md.20] Current feed value"
indicate the intended position when the motor
stops?
Action
Review the program to turn ON the PLC READY signal.
Power on the servo amplifier.
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.
Check the error code and take a corrective action.
• Review the stop program.
• 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.
Action
Check that the value in "Rotation direction selection/travel direction selection (PA14)" matches the settings
of servo amplifier. When "Rotation direction selection/travel direction selection (PA14)" has been changed,
turn the servo amplifier power supply ON again from OFF or reset the controller, and execute the home
position return.
Action
*1
[When "[Md.28] Axis feedrate"
• Check that the values in "[Pr.2] Number of pulses per rotation (AP)", "[Pr.3] Movement amount per
rotation (AL)", and "[Pr.4] Unit magnification (AM)" meet the system.
• When the servo amplifier has the electronic gear function, check that the settings meet the system.
[When "[Md.28] Axis feedrate"
• Check that the speed is not limited by the value in "[Pr.8] Speed limit value".
• In the JOG operation, check that the speed is not limited by the value in "[Pr.31] JOG speed limit value".
• In the JOG operation, check that Forward run JOG start signal [Cd.181] and Reverse run JOG start
signal [Cd.182] do not repeatedly turn ON and OFF.
Action
[When the position set in "[Md.20] Current feed value" is reached]
• Check that the values in "[Pr.2] Number of pulses per rotation (AP)", "[Pr.3] Movement amount per
rotation (AL)", and "[Pr.4] Unit magnification (AM)" meet the system.
• When the servo amplifier has the electronic gear function, check that the settings meet the system.
[When the position set in "[Md.20] Current feed value" is not reached]
• Check that the motor is not stopped by Axis stop signal [Cd.180]. If a motor is stopped by the stop
command, the value "1: stopped" is stored in "[Md.26] Axis operation status".
*1
indicates the set speed]
*1
does not indicate the set speed]
14.2 Troubleshooting by Symptom
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