2137

Common Causes

• DD encoder slave sensor internal failure (absolute position code error, communication error)
• Sensor mounting problem: gap out of range or sensor inclined/tilted
• Encoder cable or connector damage between slave sensor and drive
• Control parameter or initialization mismatch with the sensor

Troubleshooting Steps

1. 1Read the code number shown with the alarm: code 01 = Stop command has stopped; code 02 = Control parameter error; code 04 = Absolutization error; code 05 = Initialization speed too high; code 08 = Auto-set data error; code 0D = Speed too high; code 0E = Synchronization error; code 20 = Absolutization mismatch (Format-5 only)
2. 2Read the code: YY is the alarm code from the sensor. Branch on it: 42/43 = gap too narrow/wide, 40/41 = inclination error, 02 = control parameter error, 0D = speed too high, 0E = synchronization error, 3E/3F = absolute position sensor/code error, 21 = master sensor communication error.
3. 3For gap (42/43) or inclination (40/41) codes, power down and inspect the slave sensor mounting: check for looseness, debris or collision damage, and re-set the sensor-to-scale gap and alignment per the sensor mounting spec.
4. 4Check the XX byte bit6 (margin error) and bit5/bit4 warnings — these indicate the sensor is marginal before failing; correct gap/inclination before the error becomes hard.
5. 5Inspect the encoder cable and connectors at the slave sensor for bent pins, coolant ingress or chafing; reseat both ends.
6. 6For code 02 (parameter error) or 08 (auto-set data error), have Okuma service verify the encoder-related control parameters and re-run auto-set.
7. 7If the sensor itself reports absolute position code errors (3E/3F) after gap and wiring checks, replace the DD encoder slave sensor.