Originally Posted by
rdsi
First, it does not have a limit switch because it's considered limitless due to it's rotary motion. When referencing or homing the A axis (the "REF A" button in PP) all that occurs is the G53 parameter for the A axis is zeroed. However, there is an optional homing switch P/N 31921 that can be used to home the A axis using the accessory input. This option can be enabled by ticking the PP settings menu option: "4th Axis Homing" box. PP does not use soft limits on the A axis so the homing routine settles on the homing switch trip point.