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Limits & Homing

How to home

  • From the enabled state, hold SHIFT and press MENU to start homing. Axis moves in your configured Homing Direction until the limit switch triggers, backs off by Backoff Distance, and sets position to zero.

  • If the switch never triggers or triggers immediately, check wiring, polarity (Settings → Limit Pin), and the Wiring examples.

  • If a limit error appears during normal motion (Status 101), the controller stops; clear the cause and re-enable to continue.

Free movement when home position is unknown

Axis will freely rotate the motor when the home position is unknown (homing sequence not yet performed) until it reaches a limit switch where it will either stop or reverse depending on the Bounce setting.

If Bounce is Forward or Both and the motor is moving in the forward direction then the motor will reverse when the limit switch is triggered (position B). The motor will overshoot by an amount ΔL+ which depends on the current motor velocity and acceleration. If Bounce is not enabled for the forward direction then the motor will just stop when the limit switch is triggered (position B).

If Bounce is Backward or Both and the motor is moving in the backward direction then the motor will reverse if the limit switch is triggered (position A). The motor will overshoot by an amount ΔL- which depends on the current motor velocity and acceleration. If Bounce is not enabled for the backward direction then the motor will just stop when the limit switch is triggered (position A).

E.g. If two limit switches are connected in parallel and Bounce is Both, if a continuous motion is started by long pressing A- or A+ then the motor will continuously move between the two limit switches.

Movement with home position known

If the home position is known (successful homing sequence performed) then the motor is allowed to move between zero (position X0) and position-max (position Xm). The allowed range of motion is denoted in the next figure as Sm.

In the Sm range there must be no trigger from any limit switch. If the limit switch is triggered while the motor moves between X0 and Xm then axis will halt and indicate an error has occurred.

Backoff distance

Sometimes we want the home position to be at some specific distance from the limit switch and is denoted by the symbol Sb in the next figure. The distance Sb is called the Backoff distance and is configurable via the backoff-distance parameter.

test change