Okuma Alarm-P 0878 MCS Illegal command

Okuma Alarm-P 0878 MCS Illegal command
The NC and the inverter unit exchange commands and responses through the servo link. In this communication, the NC sent an abnormal or inexecutable command to the inverter unit.

Axis name or none (spindle)



10: Positioning mode Command point number over
11: Positioning mode Negative command value
12: Positioning mode Larger command value (specified position > 360 deg for rotary axis)
13: Positioning mode RPositioning point table not transmitted
14: Positioning mode Non-rotating axis
15: Positioning mode Command format other than points
16: Positioning mode Positioning sub-mode error
21: Parameter change Parameter number out of specifable range
22: Mode Undefined mode
23: Mode Positioning/tool path mode condition
24: Coordinate system Coordinate system designation error
30: Unused bit is ON in the bit commands for controlling the S-link A buffer.
31: Unused bit is ON among the bit data in the S-link B buffer.
40: AT mode is selected without reception of time synchronization command.

YYYY= Error data

X in the range from 10 to 16 shows the positioning sub-mode.
0:Program mode 1:Search mode 2:PH mode 3:Teach mode

Probable Faulty Locations
– Inverter unit not compatible with NC software
– Inverter unit control board
– NC software

Okuma Alarm-P 0878 MCS Illegal command