Before modifying motion steps via INSERT, MODIFY, or DELETE, which condition must be true?

• A. HOLD button must be pressed
• B. AREA key must be active
• C. SERVO power must be ON
• D. START button must be pressed

Answer: (C)

Modifying motion steps requires the servo drives to be powered. When the servo power is ON, the servo amplifiers and drive electronics are energized, allowing the controller to write and apply changes through INSERT, MODIFY, or DELETE. If servo power is off, the axes are de-energized, the motion path can’t be altered, and the system typically blocks edits to prevent any unintended movement. The other actions (holding, area selection, or starting) do not enable editing; they relate to safety, context, or execution, not to authoring or changing the motion program. So the necessary condition is that SERVO power must be ON.