Rapid move machine to Home 1 position.
G28 is a G-code used for returning the machine to a predefined home position or reference point. It is used to command the machine to move to a specific location, usually the machine's zero point or home position, where all of its axes are at their lowest mechanical limits. This location is often used as a reference point for homing or for setting the machine's coordinate system.
The G28 command is usually followed by one or more axis words, such as X, Y, and Z, to specify which axes should move to the home position. For example, G28 X0 Y0 Z0 would move the X, Y, and Z axes to their home positions.
If intermediate move is specified them machine will rapid move to intermediate position first and only axes specified will move to final position.
This command is often used with G91. For example: G91 G28 Z0
G28 <X..W>
G28