Before a machine can run in automatic mode, it must first be ______.

• A. Calibrated
• B. Reset
• C. Serviced
• D. Homed

Answer: (D)

The main idea is establishing a definite reference for all moving axes before automatic operation. Homing moves each axis to a known home position using limit or home sensors, setting the machine’s zero point (origin). With this defined origin, every subsequent automatic move has a reliable starting point, so positions are accurate and repeatable. Without homing, the controller doesn’t know where it is in space, so automatic commands could drift or collide. Calibration adjusts measurement accuracy but doesn’t establish a fixed origin; reset clears faults but doesn’t define a reference; servicing is maintenance and doesn’t set the coordinate system.