Mitsubishi Electric MELSEC iQ-R Series User Manual page 186

Necessary slave object
When using MC_MoveAbsolute, set the following slave object to the axis.
• Target position
If the above slave object is not set, the error "Necessary Slave Object Unset" (error code: 1AA8H) will occur, and the axis will
not start.
For details of the slave object setting, refer to the following.

Page 41 Axis Assignment
6 AXIS CONTROL FUNCTION
184
6.1 Single Axis Positioning Control