M Code Reference

M-Code Reference

This reference covers standard RepRap M-codes and proprietary FlashForge extensions supported via TCP port 8899.

Standard RepRap M-Codes

Stepper Control

Code	Function	Parameters	Description
M17	Enable Steppers	None	Enable all stepper motors
M18	Disable Steppers	None	Disable all stepper motors

Warning (M18): Disabling steppers may cause the Z-axis to drop due to gravity.

Job Control

Code	Function	Parameters	Description
M23	Select File	path	Select file for printing
M24	Start/Resume	None	Start selected file or resume paused job
M25	Pause Print	None	Pause current print job
M26	Stop Print	None	Cancel current print job immediately

M23 - Select File

Selects a file from printer storage for printing.

Command Format:

~M23 0:<file_path>

Path Formats:

• 0:/user/<filename> - User storage path
• /data/<filename> - Data storage path

Examples:

~M23 0:/user/Benchy.gcode
~M23 /data/Model.3mf

Response:

CMD M23 Received.
ok

M26 - Stop Print

Important: After stopping via TCP, the printer will not be controllable until the cancelled job dialog is manually cleared from the printer's screen.

Modern Printers (5M/AD5X): The HTTP API provides a way to programmatically clear the stopped state using stateCtrl_cmd:

POST http://10.0.0.42:8898/control
Content-Type: application/json

{
  "serialNumber": "SNADVA5MXXXXX",
  "checkCode": "12345",
  "payload": {
    "cmd": "stateCtrl_cmd",
    "args": {
      "action": "setClearPlatform"
    }
  }
}

This dismisses the on-screen dialog and returns the printer to a controllable state.

Status Queries

Code	Function	Parameters	Description
M27	Report Status	None	Get print job progress
M105	Get Temperatures	None	Get current/target temps
M114	Get Position	None	Get current XYZE position
M115	Get Firmware Info	None	Get printer details
M119	Endstop Status	None	Get endstops and status

M115 - Get Firmware Info

Response:

CMD M115 Received.
Machine Type: Flashforge Adventurer 5M Pro
Machine Name: Adventurer 5M Pro
Firmware: v3.1.5
SN: SNXXXXXXX1234
X: 220 Y: 220 Z: 220
Tool Count: 1
Mac Address:XX:XX:XX:XX:XX:XX
ok

M105 - Get Temperatures

Response (Modern Format):

CMD M105 Received.
T0:17.9/0.0 T1:0.0/0.0 B:18.5/0.0
ok

Response (Legacy Format):

CMD M105 Received.
T0:22 /0 B:11/0
ok

Field	Description
T0	Primary extruder (current/target)
T1	Secondary extruder (current/target)
B	Heated bed (current/target)

M119 - Endstop Status

Response:

CMD M119 Received.
Endstop: X-max: 110 Y-max: 110 Z-min: 0
MachineStatus: READY
MoveMode: READY
Status: S:1 L:0 J:0 F:0
LED: 1
CurrentFile:
ok

Field	Description
Endstop	X, Y, Z endstop states
MachineStatus	READY, BUILDING_FROM_SD, PAUSED, BUSY, BUILDING_COMPLETED
MoveMode	MOVING, PAUSED, READY, WAIT_ON_TOOL, HOMING
LED	1 = ON, 0 = OFF
CurrentFile	Active print filename

Temperature Control

Code	Function	Parameters	Description
M104	Set Nozzle Temp	S	Set extruder temp (async)
M140	Set Bed Temp	S	Set bed temp (async)

M104 - Set Extruder Temperature

Command: ~M104 S<temperature>

Value	Description
S0	Turn off extruder heating
S210	Set to 210C

Examples:

~M104 S210     (Heat to 210C)
~M104 S0       (Turn off)

M140 - Set Bed Temperature

Command: ~M140 S<temperature>

Value	Description
S0	Turn off bed heating
S60	Set to 60C

Fan Control

Code	Function	Parameters	Description
M106	Fan On	[S]	Turn fan on (optional speed)
M107	Fan Off	None	Turn fan off

M106 - Fan On

Command: ~M106 [S<speed>]

Model	Speed Support
Adventurer 3	On/Off only (no speed control)
5M Series	Variable speed S0-255

Examples:

~M106           (Full speed)
~M106 S128      (50% speed - 5M only)
~M106 S255      (Full speed - 5M only)

Safety

Code	Function	Parameters	Description
M112	Emergency Stop	None	Immediate halt

Warning: M112 causes an immediate halt of all operations. On some printers, axes are homed and heaters are turned off. The print job cannot be recovered after triggering M112.

Proprietary FlashForge M-Codes

Session Control

Code	Function	Description
M601	Connect WiFi	Legacy session initialization
M602	Disconnect WiFi	Legacy session termination

M601 - Request Control

Required before sending most commands.

Command: ~M601

Success Response:

CMD M601 Received.
Control Success V2.1.
ok

Failure Response:

CMD M601 Received.
Control Failed.

Failure indicates another client is connected or previous session was not properly closed.

M602 - Release Control

Required before disconnecting.

Command: ~M602

Response:

CMD M602 Received.
Control Release.
ok

Printer Configuration

Code	Function	Parameters	Description
M610	Rename Printer		Set printer display name

Warning: Triggers network service restart, briefly dropping the connection.

Calibration

Code	Function	Description
M650	Get Calibration	Returns internal calibration values

Note: Returns calibration values, NOT model identification.

File Operations

Code	Function	Description
M661	List Files	Returns file list with special parsing
M662	Get Thumbnail	Returns PNG binary with custom header

M661 - List Files

Command: ~M661

Important: Data is sent AFTER the ok response.

Response:

CMD M661 Received.
ok
D::/data/File1.3mf::/data/File2.gcode...

The file list uses special delimiters and requires custom parsing.

M662 - Get Thumbnail

Command: ~M662 <file_path>

Example: ~M662 /data/Model.gcode

Important: Binary PNG data is sent AFTER the ok response. The PNG has a custom header (0xa2a22a2a).

LED Control

Code	Function	Parameters	Description
M144	LED On	None	Turn LED on (EEPROM write)
M145	LED Off	None	Turn LED off (EEPROM write)
M146	LED RGB	r g b F	Set LED color (preferred)

M146 - LED Control (Preferred)

Command: ~M146 r<red> g<green> b<blue> F0

Parameter	Range	Description
r	0-255	Red intensity
g	0-255	Green intensity
b	0-255	Blue intensity
F	0	Control flag

Examples:

~M146 r255 g255 b255 F0    (White, ON)
~M146 r255 g0 b0 F0         (Red)
~M146 r0 g0 b0 F0           (OFF)

Warning (M144/M145): These commands write to EEPROM. Avoid frequent use to prevent EEPROM wear. Use M146 instead.

Extended Position

Code	Function	Description
M663	Get XYZEF	Enhanced position query (serial passthrough)

Binary Upload (Legacy)

Code	Function	Description
M28	Start Upload	Begin binary file transfer
M29	End Upload	Complete binary file transfer

Note: For legacy printers (A3/A4) only. Modern printers should use HTTP /uploadGcode.

See TCP Protocol for complete M28/M29 documentation.

Stubbed Commands

Some commands are present in firmware but non-functional:

Code	Status	Notes
M108	Stubbed	Cancel Heat Wait - non-functional on A3

Command Summary Table

Code	Category	A3	A4	5M	AD5X
M17	Stepper	Yes	Yes	Yes	Yes
M18	Stepper	Yes	Yes	Yes	Yes
M23	Job	Yes	Yes	Yes	Yes
M24	Job	Yes	Yes	Yes	Yes
M25	Job	Yes	Yes	Yes	Yes
M26	Job	Yes	Yes	Yes	Yes
M27	Status	Yes	Yes	Yes	Yes
M104	Temp	Yes	Yes	Yes	Yes
M105	Temp	Yes	Yes	Yes	Yes
M106	Fan	Yes*	Yes*	Yes	Yes
M107	Fan	Yes	Yes	Yes	Yes
M112	Safety	Yes	Yes	Yes	Yes
M114	Status	Yes	Yes	Yes	Yes
M115	Status	Yes	Yes	Yes	Yes
M119	Status	Yes	Yes	Yes	Yes
M140	Temp	Yes	Yes	Yes	Yes
M601	Session	Yes	Yes	Yes	Yes
M602	Session	Yes	Yes	Yes	Yes
M610	Config	Yes	Yes	Yes	Yes
M650	Calib	Yes	Yes	Yes	Yes
M661	File	Yes	Yes	Yes	Yes
M662	File	Yes	Yes	Yes	Yes
M663	Status	Yes	Yes	Yes	Yes
M146	LED	Yes	Yes	Yes	Yes

*A3/A4: On/Off only (no variable speed)