0738

Common Causes

• Faulty DD encoder
• Damaged or loose encoder link cable or connector
• Encoder fuse voltage outside the normal 10.6-13.8 V range
• Incompatible encoder parameters, protocol version, or data format
• Faulty inverter unit control board

Troubleshooting Steps

1. 1Read the code number shown with the alarm: code XX=0 = Failure during reset step; code XX=1 = Failure during network address setting; code XX=2 = Failure requesting basic communication information; code XX=3 = Failure during communication software version change; 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. 2Record the full code XXYYZZZZ. XX identifies the initialization step where it stopped (0=reset through 7=AT mode start) and YY identifies the error type.
3. 3If XXYY reads $FFFF, ZZZZ is the measured encoder fuse voltage; verify the encoder supply is within 10.6-13.8 V and investigate the supply if it is out of range.
4. 4If YY=6, use ZZZZ to identify the parameter issue (insufficient parameters received, multi-turn detection range exceeded, or incompatible protocol/data format/abbreviated mode) and correct the encoder configuration.
5. 5If YY=5, decode ZZZZ with MCS DD Encoder error alarm 1136 for the detailed encoder fault.
6. 6Inspect and reseat the encoder link cables and connectors between the DD encoder and the inverter unit; replace any damaged cable.
7. 7If wiring and supply voltage check out, replace the DD encoder; if the fault remains, suspect the inverter unit control board and contact Okuma service.