0736

Common Causes

• DD encoder failure (internal sensor or electronics)
• Encoder gap out of tolerance (too narrow or too wide) between sensor and scale
• Sensor head inclination misalignment after mechanical disturbance
• Communication error on the encoder signal line (cable/connector damage)
• Absolutization/initialization failure after power-up or excessive speed at startup

Troubleshooting Steps

1. 1Read the code number shown with the alarm: code XX bit7 = Error bit set (1 = error present); code XX bit6 = Absolute position sensor margin warning; code XX bit5 = Gap warning: steady = gap small, toggling = gap large; code XX bit4 = Inclination warning: steady = CCW large, toggling = CW large; code XX bit3 = Auto set mode active (1 = auto mode); code XX bit2 = Communication error, toggles when detected; code XX bit1,0 = Error bit number of the absolute position code (2-bit value); code YY=01 = Stop command has stopped
2. 2Read the YY portion of the XXYYZZZZ code on screen to identify the failure: e.g. 02 control parameter error, 04 absolutization error, 05 initialization speed too high, 0D speed too high, 0E synchronization error, 42 gap narrow, 43 gap wide, 40/41 inclination error.
3. 3Also check the XX status bits: bit5 toggling indicates an unstable gap, bit4 indicates inclination warning, bit2 toggling indicates a communication error on the encoder line.
4. 4Inspect the encoder cable and connectors between the DD encoder and the control for looseness, crushed sections or coolant ingress; reseat and secure them.
5. 5For gap (42/43) or inclination (40/41) codes, check the sensor head mounting for looseness or shift and verify the gap and alignment are within the encoder's specified setup.
6. 6For absolutization (04) or initialization-speed (05) codes, power the machine off, ensure the axis is stationary at power-up, and restart; repeated failure points to the encoder.
7. 7If the error persists, the DD encoder itself is the probable faulty part; record the full code and object and contact Okuma service for replacement.