M911 confirmation / questions



  • Is M911 always called when VIN is reduced below the set value? I'm hoping it is, but want to be certain it is always called, not just under certain conditions..

    Thanks


  • Moderator

    Well it would be called if an SD card print is in progress and the voltage threshold is met. I don't think it would be called when the printer is idle.



  • @Phaedrux My concern is there are other times when the steppers are potentially moving (ex: mesh bed leveling). We are exploring adding the stepper brake for Z back into our design as a safeguard and are just wanting to cover our bases. Maybe M911 isn't necessary for outside of print jobs..? I'm just trying to cover my bases to guarantee no damage can come to the Duet 3 if it tries to moves the steppers while the brake is engaged (off state).


  • Moderator

    @oozeBot said in M911 confirmation / questions:

    My concern is there are other times when the steppers are potentially moving (ex: mesh bed leveling).

    Well the purpose of the feature is resuming a print in progress after a power failure, so resuming a G29 wouldn't make sense.

    Are you worried that the movement to lift the Z axis would happen while the breaks are engaged? Given that you wouldn't have the breaks enabled during a print I don't think that's a concern.



  • @Phaedrux I understand.. was just covering bases. The brake we implemented works great, just wanted to better safeguard the system. Another idea I had was to add an if statement to daemon.g which monitors VIN and handles it that way.. but that will require testing as I’m not sure how safe it is to loop the daemon sub-second.


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