Fanuc alarm: 5402 - SPL:ILLEGAL AXIS MOVING(M series)

A movement is made along an axis that is not the spline interpolation
axis.
For example, in three-dimensional tool compensation mode using an
offset vector of which components are the X-, Y-, and Z-axes, when
two-axis spline interpolation is performed with the two spline axes set
to the X- and Y-axes, a movement along the Z-axis occurs, resulting
in this alarm.