Every motion FB you call makes sense once you hold one rule in your head: an axis is always in exactly one state, and commands move it between them. Skip memorising the diagram and drive it instead.
Start in Disabled. Each command is legal only from certain states; try an illegal one and the axis tells you so. That is exactly why a MoveAbsolute "does nothing" on a disabled axis.
🧭 One state, always. There's no "in between". After a move completes, the axis returns to Standstill; after a fault it sits in ErrorStop until you MC_Reset. Your code can always ask "where am I?" and get one answer.
🚧 ErrorStop wins. A fault from any state drops the axis straight to ErrorStop, and the only way out is MC_Reset back to Standstill (or Disabled). That guaranteed fallback state is what the whole model is built around.
An axis is in ErrorStop. You send MC_MoveAbsolute. What happens?