1137

Common Causes

• Faulty DD encoder (slave sensor)
• Gap between sensor head and scale too narrow or too wide (YY=42/43)
• Sensor head inclination out of tolerance (YY=40/41)
• Contamination or damage on the absolute position track causing code errors (YY=3E/3F)
• Encoder communication link problem (YY=21 or XX bit2)

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 code. The YY byte is the alarm code: 0D = speed too high, 0E = synchronization error, 42/43 = gap narrow/wide, 40/41 = inclination error, 3E/3F = absolute position sensor code/check error, 21 = master sensor communication error.
3. 3Check the XX status byte: bit6 warns of low absolute-position margin, bit5 flags a gap warning, bit4 an inclination warning, bit2 a communication error - these point to mounting condition versus link problems.
4. 4For gap or inclination codes (40-43), power down and inspect the slave sensor head mounting: verify the head-to-scale gap and alignment are within spec and that nothing has loosened or shifted.
5. 5For absolute code errors (3E/3F), clean the scale and sensor head of oil, coolant, and chips, and check for scratches on the track.
6. 6For communication or absolutization mismatch codes (20/21), inspect and reseat the encoder link cable and connectors between the slave sensor, master sensor, and inverter unit.
7. 7If the error persists after cleaning, alignment, and cable checks, replace the DD encoder (slave sensor); record the full XXYYZZZZ code and contact Okuma service.