0863

Common Causes

• Damaged or loose encoder link cable or connector on the reported axis/spindle
• Failed feedback device: motor encoder, ABSOSCALE, axis-mount encoder, or independent encoder
• Faulty inverter unit control board
• Electrical noise or poor shielding/grounding on the encoder link cable

Troubleshooting Steps

1. 1Read the code number shown with the alarm: code YY=00 = Error detected in the motor encoder; code YY=01 = Error detected in the axis-mount encoder; code YY=02 = Error detected in the independent encoder; code YY=03 = Error detected in the ABSOSCALE; code ZZZZ bit15 = Communication error raised by the independent encoder; code ZZZZ bit14 = Communication error raised by ABSOSCALE 2; code ZZZZ bit13 = Communication error raised by ABSOSCALE or axis-mount encoder; code ZZZZ bit12 = Communication error raised by the monitor encoder
2. 2Read the code on screen: YY tells you which device reported the error (00 motor encoder, 01 axis-mount encoder, 02 independent encoder, 03 ABSOSCALE); the ZZZZ bits show the error type (bit0 time-out, bit1 parity, bit5 CRC, bit6 modulation code, bit10 AT-mode transmission loop).
3. 3Power down and lock out the machine; allow the drive DC bus to discharge before touching connectors.
4. 4Inspect and reseat the encoder link cable and connectors at both the feedback device end and the inverter end for the reported axis; look for crushed cable, coolant ingress, bent pins, or a broken shield.
5. 5If the cable and connectors are good, swap or substitute the suspect feedback device indicated by YY (motor encoder, axis-mount encoder, independent encoder, or ABSOSCALE) to isolate it.
6. 6If the error follows neither cable nor encoder, the inverter unit control board is suspect; have it checked or replaced.
7. 7If it returns after these checks, record the alarm number, full XXYYZZZZ code and object and contact Okuma service.