M420 - Bed Leveling State

motion Get and/or set bed leveling state and parameters AUTO_BED_LEVELING_(3POINT|LINEAR|BILINEAR|UBL)|MESH_BED_LEVELING

Get and/or set bed leveling state. For mesh-based leveling systems use Z parameter to set the Z Fade Height.

With AUTO_BED_LEVELING_UBL you can use L to load a mesh from EEPROM.

The “current position” may change in response to M420 Sn.
By default G28 disables bed leveling. Follow with M420 S to turn leveling on.
- With ENABLE_LEVELING_AFTER_G28 leveling will always be enabled after G28.
- With RESTORE_LEVELING_AFTER_G28 leveling is restored to whatever state it was in before G28.
For multi-axis machines (I_DRIVER_TYPE defined) without implementation of inverse kinematics, bed leveling produces wrong results while the toolhead is not oriented vertical and perpendicular to the bed and must be turned off with M420 S0.

M420 [C<bool>] [L<int>] [S<bool>] [T<0|1|4>] [V<bool>] [Z<linear>]

`[C<bool>]`	Center the mesh on the mean of the lowest and highest points
`[L<int>]`	Load mesh from EEPROM index (Requires `AUTO_BED_LEVELING_UBL` and `EEPROM_SETTINGS`)
`[S<bool>]`	Set enabled or disabled. A valid mesh is required to enable bed leveling. If the mesh is invalid / incomplete leveling will not be enabled.
`[T<0\|1\|4>]`	Format to print the mesh data `T0`: Human readable `T1`: CSV `T4`: Compact
`[V<bool>]`	Verbose: Print the stored mesh / matrix data
`[Z<linear>]`	Set Z fade height (Requires `ENABLE_LEVELING_FADE_HEIGHT`) With Fade enabled, bed leveling correction is gradually reduced as the nozzle gets closer to the Fade height. Above the Fade height no bed leveling compensation is applied at all, so movement is machine true. Set to 0 to disable fade, and leveling compensation will be fully applied to all layers of the print.