When should zero return be performed?

• A. After a fault only.
• B. After installation or after a fault, to move axes to their reference trigger.
• C. Before turning on the power.
• D. During normal jogging to test speed.

Answer: (B)

Zero return establishes a known home position for the axes by moving each axis to its reference trigger (home switch) and zeroing the encoder counts there. This sets the controller’s coordinate system to a reliable origin, which is essential before doing any precise moves.

You perform zero return after installation or after a fault. After installation, you need to locate the axes to their true home so the system can calibrate itself correctly. After a fault, the position information may be lost or uncertain, so re-homing ensures subsequent moves start from a known reference. It’s not done before turning on power, since the system can’t move or read the reference switches without power. It’s also not used during normal jogging to test speed, because jogging is for movement tests, not for establishing or re-establishing the reference position.