---
tag: m0306
title: Model predictive temperature control
brief: Set MPC values for a hotend.
author: CRCinAU

requires: MPCTEMP
group: thermal
since: 2.0.9.4

codes: [ M306 ]

notes:
  - Requires `MPCTEMP`.
  - View current values with [`M306`](/docs/gcode/M306.html) and no parameters.
  - If `EEPROM_SETTINGS` is enabled, all calibration values are saved with [`M500`](/docs/gcode/M500.html), loaded with [`M501`](/docs/gcode/M501.html), and reset with [`M502`](/docs/gcode/M502.html).
  - Heater Power (P) is related to the heater cartridge in the hotend. Most printers have 30 or 40 watt heaters.
  - '`M306 T` will move your hotend to 1mm above the bed for optimal calibration. You should ensure your hotend and print bed are free from debris before running an auto-tune.'
  - See [the Marlin MPC documentation](/docs/features/model_predictive_control.html) for more information about MPC parameters.

parameters:
  -
    tag: A
    optional: true
    description: Ambient heat transfer coefficient (no fan).
    values:
      -
        tag: value
        type: float
  -
    tag: C
    optional: true
    description: Heatblock Capacity (joules/kelvin)
    values:
      -
        tag: value
        type: float
  -
    tag: E
    optional: true
    description: Extruder index. If omitted, the command applies to the active extruder.
    values:
      -
        tag: index
        type: int
  -
    tag: F
    optional: true
    description: Ambient heat transfer coefficient (fan on full).
    values:
      -
        tag: value
        type: float
  -
    tag: H
    optional: true
    description: Filament Heat Capacity (joules/kelvin/mm)
    values:
      -
        tag: value
        type: float
  -
    tag: P
    optional: true
    description: Heater power in watts
    values:
      -
        tag: value
        type: float
  -
    tag: R
    optional: true
    description: Sensor responsiveness (= transfer coefficient / heat capacity).
    values:
      -
        tag: value
        type: float
  -
    tag: T
    optional: true
    description: Autotune the selected extruder.

examples:
-
  pre: 'Configure MPCTEMP for 40W hotend heater'
  code:
    - M306 P40
-
  pre: 'Configure MPCTEMP for 70W hotend heater'
  code:
    - M306 P70
-
  pre: 'Perform MPCTEMP auto-tune - after setting heater element power'
  code:
    - M306 T
---