On the FANUC robot, the statement 'only Axes 1, 3, and 5 servo motors have serial pulse encoders' is true.

• A. It depends on the model
• B. True
• C. False
• D. Encoders are on all axes

Answer: (C)

Position feedback on every servo axis is what makes FANUC robot motion accurate and controllable. Each joint relies on its motor’s encoder to tell the controller exactly where that joint is and how fast it’s moving, so it can correct any error in real time. Because of that closed-loop requirement, it isn’t correct to say that only some axes have serial pulse encoders. In practice, the servo motors on all axes include encoder feedback, often serial pulse encoders, to provide the necessary position data for all joints. That’s why this statement isn’t true.