3138

Common Causes

• DD encoder failure
• Encoder link cable or connector fault between encoder and inverter unit
• Inverter unit control board failure
• Abnormal encoder fuse voltage (outside 10.6–13.8 V) indicating a power/wiring problem
• Incompatible encoder parameters, protocol version or data format

Troubleshooting Steps

1. 1Read the code number shown with the alarm: code XX=0 = Failure at reset step of encoder link initialization; code XX=1 = Failure at network address setting; code XX=2 = Failure requesting basic communication information; code XX=3 = Failure changing communication software version; code XX=4 = Failure acquiring device information; code XX=5 = Failure during parameter change; code XX=6 = Failure at position detection start; code XX=7 = Failure at AT mode start
2. 2Read the code: XX shows which initialization step failed (0=reset, 1=network address setting, 2=basic communication info request, 3=comm software version change, 4=device info acquisition, 5=parameter change, 6=position detection start, 7=AT mode start); YY shows the error type (0=communication error, 1-3=transmission/reception time over, 4=bad response address, 5=bad response code, 6=parameter error).
3. 3If XXYY shows $FFFF, the encoder fuse voltage is abnormal: ZZZZ is the measured voltage (12 V = $9980; normal 10.6–13.8 V). Lock out power, then check the encoder power supply wiring and fuse before proceeding.
4. 4Power down and inspect the encoder link cables and connectors end to end: reseat connectors, check for bent pins, coolant ingress and chafed cable, especially at moving-axis cable carriers.
5. 5For YY=6 (parameter error), note the ZZZZ value: 1=insufficient parameters received, 2=incompatible basic communication info, 3=multi-turn detection range over, 4=protocol version incompatible, 5=position data format incompatible, 6=abbreviated data mode incompatible — this points to an encoder/control mismatch; have Okuma service verify compatibility.
6. 6If cables and connectors check out, swap or replace the DD encoder; if the fault follows the drive side, replace the inverter unit control board.
7. 7If the alarm returns after these checks, record the full XXYYZZZZ code and object and contact Okuma service.