0737

Common Causes

• Faulty DD encoder slave sensor
• Sensor-to-scale gap too narrow or too wide (codes 42/43) from mechanical shift or contamination
• Sensor inclination out of tolerance (codes 40/41)
• Encoder link communication disturbance (code 21 or XX bit2)
• Axis moved faster than the sensor allows during initialization or operation (codes 05/0D)

Troubleshooting Steps

1. 1Read the code number shown with the alarm: code YY=01 = Stop command has stopped; code YY=02 = Control parameter error; code YY=04 = Absolutization error; code YY=05 = Initialization speed too high; code YY=08 = Auto-set-data error; code YY=0D = Speed too high; code YY=0E = Synchronization error; code YY=20 = Absolutization mismatch (Format-5 only)
2. 2Read the full code. The YY byte is the sensor's alarm code and tells you the fault type; the XX byte gives positional data status bits (bit7 error, bit6 margin warning, bit5 gap warning, bit4 inclination warning, bit2 communication error).
3. 3Code 0D or 05 (speed too high): check whether the axis was moved or bumped while the error occurred; clear the alarm and retry at normal speed before suspecting hardware.
4. 4Codes 40/41 (inclination error) or 42/43 (gap narrow/wide): inspect the slave sensor mounting on the named axis for looseness, and check the sensor/scale gap and cleanliness; remove any chips or coolant film on the scale.
5. 5Code 21 or XX bit2 (communication error): inspect and reseat the encoder link cable and connectors at the slave sensor and inverter unit; check for damage or coolant ingress.
6. 6Codes 3E/3F (absolute position sensor code/check error), 04 (absolutization error) or 20 (absolutization mismatch): the sensor's absolute data is invalid; the sensor itself is the probable faulty part.
7. 7If wiring, gap and mounting are sound, replace the DD encoder slave sensor. If the alarm returns, record the full XXYYZZZZ code and contact Okuma service.