Yaskawa MP940 Reference Manual - Manual (Page 384)

MotionSuite™ MP940 Machine Controller Reference Manual Troubleshooting
10-31
A.Cb
A.Cb is the alarm display for encoder echoback errors. The alarm output
appears below.
Note: The x indicates the output transistor is OFF (alarm state).
Status when Alarm Occurred
Alarm Output
Alarm Code Output ALM Output
ALO1 ALO2 ALO3
>_ x › _ x
Cause Remedy
A Mistaken encoder wiring. Review the encoder wiring.
B Encoder defective. Replace servo motor.
C Servo amplifier defective. Replace servo amplifier.
Alarm occurs at power ON A, B, C