1165

Common Causes

• Faulty motor encoder on the named axis or spindle
• Damaged or loose encoder link cable or connector
• Failed inverter unit control board
• Encoder parameter mismatch (incomplete parameter transfer or multi-rotation range mismatch)

Troubleshooting Steps

1. 1Read the code number shown with the alarm: code XX=0 = Failure during link reset; code XX=1 = Failure during network address setting; code XX=2 = Failure requesting basic communication information; code XX=3 = Failure changing communication version; code XX=4 = Failure acquiring device information; code XX=5 = Failure during parameter change; code XX=6 = Failure at AT (auto) mode start; code YY=0 = Communication error; ZZZZ shows encoder link error status C2ERR
2. 2Read the code on screen: XX shows which link sequence step failed (e.g. 2 = basic communication info request, 5 = parameter change), YY shows the error type, and ZZZZ gives detail.
3. 3If YY=6 (parameter error), check ZZZZ: 1 means not all required parameters arrived, 2 means communication basic info is incompatible, 3 means the multi-rotation detection range does not match — re-check the encoder-related setup for that axis.
4. 4If YY=0 (communication error), power down and lock out, then inspect and reseat the encoder link cable connectors at both the motor encoder and the inverter unit; look for bent pins, coolant ingress, or chafed cable along the axis run.
5. 5Swap or substitute the encoder link cable with a known-good one if available; a broken link cable is the most common field cause.
6. 6If the cable and connectors are good, the motor encoder itself is suspect — replace the encoder on the named axis/spindle.
7. 7Only after cable and encoder are eliminated should the inverter unit control board be replaced; if the alarm returns, record the full XXYYZZZZ code and contact Okuma service.