1190

Common Causes

• Failed independent position encoder
• Encoder link cable or connector fault interrupting the initialization handshake
• Failed inverter unit control board
• Encoder parameter problem (incompatible communication data or multi-turn range exceeded)

Troubleshooting Steps

1. 1Read the code number shown with the alarm: code XX=0 = Failure during reset step; code XX=1 = Failure during net 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 AT mode start; code YY=0 = Communication error; ZZZZ is the encoder link error status
2. 2Read the XX code to see how far initialization got: 0=reset, 1=net address setting, 2=basic communication info request, 3=communication software version change, 4=device info acquisition, 5=parameter change, 6=AT mode start - an early failure (0-2) points to wiring or a dead encoder.
3. 3Read YY for the failure type: 0=communication error, 1/2/3=transmission or reception time-over, 4=wrong response address, 5=wrong response code, 6=parameter error.
4. 4If YY=6, the ZZZZ data tells more: 1=too few parameters received, 2=incompatible basic communication information, 3=multi-turn detection range exceeded - this points to an encoder/data compatibility issue rather than wiring.
5. 5Lock out the machine and allow the drive to discharge, then inspect and reseat the encoder link cable and connectors between the independent encoder and the inverter; check for damage, bent pins, and coolant ingress.
6. 6If the link is good, replace the independent position encoder; if the failure persists, the inverter unit control board is the remaining suspect - contact Okuma service with the alarm number, object, and full code.