2691

Common Causes

• Failed Rotary encoder 1 (internal signal amplitude or offset fault)
• Encoder cable or connector damage causing communication error (status bit6)
• Contamination or damage on the encoder read head causing small/excessive signal amplitude
• Illegal control parameter reported by the encoder (YY=02)

Troubleshooting Steps

1. 1Read the code number shown with the alarm: code XX bit7 = Encoder alarm flag set; code XX bit6 = Encoder communication error; code XX=8X = Encoder output amplitude is normal; code XX=9X = Encoder output amplitude is small; code XX=AX = Encoder output amplitude is large; code XX=BX = Encoder output amplitude is far too small; code YY=00 = Encoder not started; code YY=01 = Stopped by stop command
2. 2Read the code on screen: XX is the encoder status (bit7=alarm, bit6=communication error; 8X normal amplitude, 9X/BX amplitude too small, AX too large), YY is the encoder's own alarm code, ZZZZ is the position data per pitch.
3. 3If XX shows bit6 (communication error), inspect the encoder cable and connectors for that axis for damage, loose seating, or oil ingress before condemning the encoder.
4. 4Use YY to narrow the fault: 11-17 indicate AD offset voltage drift, 25-2F indicate signal amplitude out of range, 0E a synchronous mistake, 0F illegal excitation output, 80-FF an internal CPU fault.
5. 5If YY=02 (illegal control parameter), verify the encoder-related control data for that axis before replacing hardware.
6. 6If the code points to the encoder itself, replace Rotary encoder 1 as directed by the manual.
7. 7If the alarm returns after replacement, record the alarm number, full XXYYZZZZ code and axis object and contact Okuma service.