2163

Common Causes

• Faulty motor encoder, ABSO SCALE, encoder with shaft, or stand-alone encoder on the indicated axis
• Damaged encoder link cable or loose/contaminated connector
• Electrical noise on the link causing CRC, parity, or format errors
• Defective inverter unit control board

Troubleshooting Steps

1. 1Read the code number shown with the alarm: code YY=00 = Error detected at the motor encoder; code YY=01 = Error detected at the position encoder with shaft; code YY=02 = Error detected at the independent position encoder; code YY=03 = Error detected at the ABSO SCALE; code ZZZZ bit15 = Communication error with a stand-alone encoder; code ZZZZ bit14 = Communication error with ABSO SCALE 2; code ZZZZ bit13 = Communication error with ABSO SCALE or encoder with shaft; code ZZZZ bit12 = Communication error with the motor encoder
2. 2Record the object (axis or spindle) and the full code. YY tells you which device reported the error: 00 = motor encoder, 01 = position encoder with shaft, 02 = independent position encoder, 03 = ABSO SCALE.
3. 3Decode the ZZZZ bits: bit0 time-out or bit1 parity usually means cable/connector trouble; bits 12-15 flag lost communication with a specific encoder device; bit5 CRC or bit4 format errors suggest noise or a failing encoder.
4. 4Lock out machine power, then inspect the encoder link cable and connectors for the flagged device: look for loose seating, bent pins, oil or coolant ingress, and chafed insulation; clean and reseat.
5. 5Verify the cable is routed away from power/motor leads and that shielding and grounding are intact to eliminate noise pickup.
6. 6If the error returns, test or replace the encoder identified by the YY value on that axis.
7. 7If the encoder and cabling are good, the inverter unit control board is the remaining suspect; record the alarm number, code, and object and contact Okuma service.