Optional Stop Mode

Demonstration

M334 - Enable Optional Stop Mode

Description

M334 enables optional stop mode. When enabled, M1 commands will pause program execution.

Parameters

None

Example

M334                 ; Enable optional stop mode

M1 - Optional Stop

Description

M1 performs an optional stop during program execution. The command will pause execution if optional stop mode is enabled. This is useful for debugging or manual intervention during program execution.

Parameters

None

Example

M1                    ; Optional stop (pauses if optional stop mode is enabled)

Resuming After M1 Optional Stop

After an M1 command pauses execution (when optional stop mode is enabled), you can resume using one of these methods:

Console Command

This is the primary way to resume from a suspended state.

resume

G-code Command

Serial Console Character

When you resume after an M1:

1. Position Restoration: The system restores the saved XYZ positions and state

2. Before Resume G-code: If configured, executes any before_resume_gcode

3. Motion Mode: Restores the previous motion mode (G0/G1/G2/G3)

4. File Playback: Continues playing the G-code file from where it was suspended

Configuration

You can configure custom G-code to run before resuming by setting:

before_resume_gcode M3                 ; Turn the Spindle back on

M333 - Disable Optional Stop Mode

Description

M333 disables optional stop mode. When disabled, M1 commands will not pause program execution.

Parameters

None

Example

M333                 ; Disable optional stop mode