Behavior of G-code and address letters

If a block contains only address letters without a G-command (G0, G1, G2, G3), two different behaviors can occur.

If the address letters (e.g. X200) match the motion command that was last executed, it will be treated as if this motion command were included in the block. Otherwise, the interpreter will issue an error.

A program end (M2, M30) must be present in the code, otherwise the imported program is invalid.