COORDINATES = X Y Z - The names of the axes being controlled. Only
X, Y, Z, A, B, C, U, V, W are valid. Only axes named in COORDINATES
are accepted in g-code. This has no effect on the mapping from G-code
axis names (X- Y- Z-) to joint numbers—for trivial kinematics, X is always
joint 0, A is always joint 3, and U is always joint 6, and so on. It is permitted
to write an axis name twice (e.g., X Y Y Z for a gantry machine) but this
has no effect.
Manual says (re [TRAJ]):
So, I guess that means I need to use 8 axis.