1520

Common Causes

• Master or slave axis sagged/fell after power-down, or its brake failed (power-up case, limit B)
• Master or slave axis overloaded during operation
• Servo failure on the master or slave axis (running case, limit A)

Troubleshooting Steps

1. 1Read the code number shown with the alarm: code (hex value) = The synchronization error between master and slave axes at the moment of the alarm, expressed in hexadecimal
2. 2Note the hexadecimal code shown — it is the synchronization error magnitude at the time of the alarm — and whether the alarm occurred at power-up (case 1) or during operation (case 2).
3. 3Case 1 (power-up): enter the synchronized error correction mode and correct the error using the pulse handle set to X1, then exit the mode and press RESET.
4. 4Case 2 (during operation): turn the power off and then on again to recover.
5. 5For recurring case 1 alarms, inspect the brake on the master and slave axes for proper holding when power is removed.
6. 6For recurring case 2 alarms, check for mechanical binding or overload on the master/slave axis (e.g. ZA or XA sync axis) before suspecting the servo; electrical checks of the servo drive should be done only after lockout and allowing DC bus capacitors to discharge.
7. 7If the alarm persists after these steps, record the alarm number, hex code and object axis and contact Okuma service.