M301 PID or M307 ACD?



  • Having just completed my PID tuning on my bed and hot end I get two sets of figures for each...

    10‎:‎09‎:‎12
    M307 H0
    Heater 0 model: gain 485.1, time constant 532.3, dead time 1.0, max PWM 1.00, calibration voltage 24.2, mode PID, inverted no, frequency default
    Computed PID parameters for setpoint change: P198.7, I8.675, D137.1
    Computed PID parameters for load change: P1
    ‎10‎:‎09‎:‎00

    M307 H1
    Heater 1 model: gain 599.1, time constant 279.4, dead time 4.7, max PWM 1.00, calibration voltage 24.1, mode PID, inverted no, frequency default
    Computed PID parameters for setpoint change: P17.7, I0.486, D58.3
    Computed PID parameters for load change: P17.

    My question is which figures should I use in my config.g file - M301 and PID or M307 and ACD (gain, time constant and deadtime)?


  • administrators

    Just use M307. The computed PID parameters are displayed for information only, and will be applied automatically.

    btw the reported dead time of 1.0 for the bed heater is rather low. But that may just mean that you are using a silicone heater with a built-in thermistor. If the bed temperature oscillates around the set point, try increasing that D parameter. You can do that live while the bed heater is hot.


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