Heatbed Temperatur on Prusa i3 MK3

I'm testing Repetier Server at the moment. Mostly everything works, but the heatbed temepratur isn't read by Repetier Host. It's show always 0°C - even when the heatbed is working and the LCD shows 60/60°C.
Any idea, whats wrong?


  • Normally happens if the M105 response is not known or if you have set that you have no heated bed in server config also you have. Both cause this. If you have bed configured, please post your M105 response so I can see what it might be.
  • I rechecked again: heatbed is configured, also the little green dot.
    The M105 response looks like this:

    7:07:34.967: N140 M105
    7:07:34.977: ok T:19.3 /0.0 B:18.6 /0.0 T0:19.3 /0.0 @:0 B@:0 P:20.0 A:25.1
    T is the Extruder temperatur, this one is correctly shown, B the bed, and this is shown as 0.0.
  • Ok, I see the reason. A: is causing this. Newer marlin version can now output alternative coordinates as A: B: C: as well, so B: is not always bed. So additional rule is no A: in response, which you now seem to have. 

    Can you say what P: and A: are for?

    At the moment I now have the problem of how to detect if a response is for temperatures or not. Maybe I should test if T: or T0: is present, also I know firmwares where this is not the case. All these wild additions can get really complicated.
  • Ok I understand. I asked at Prusa for the other values:

    P is the temp from the PINDA thermistor (since MK3, PINDA2 has an own thermistor)
    A is the ambient temp, measured from an sensor on the Einsy board.
  • Ok if you can at least disable reporting A: it will work. I have added an additional rule to also accept presence of T: or T0: to interpret B: as bed temperature. So on next release that should be fixed.
  • Great news, looking forward for the next release.
  • Hi @Repetier

    I to have just received my Prusa Mk3 and have noticed this issue :(

    Can continuing to use RepetierServer with no Heatbed temperature reading cause any damage? eg. over heating not turning off etc?

    Is there anyway to volunteer for beta testing or receiving early Release candidates for upcoming versions to solve this issue. Happy to do some testing and reporting I am running a Prusa Mk2, Prusa Mk3 and a Printrbot Simple metal. I am also a Pro lic. holder.
  • The error is pure cosmetic. Server does not assume B: to be a bed temperature form this condition so it just does not show the temperature, but it still gets set correctly. So nothing to worry. Just use M190 in gcode to wait for target temperature and everything is fine.

    Maybe we will have a public beta for next release since it will be the biggest update we ever had. But at the moment is is only usable if you know what is missing as transformation is not complete. Subscribe to our twitter or facebook account to get notices about such events.

  • hi @Repetier ;

    Okay this is some strange behaviour, my Prusa Mk3 has begun correctly displaying its bed temp in the box near the top right where you can quickly see or change temps (pic attached) however when looking at the graph in the control tab nothing is being reported.

    The reported temp is correct and matches the temp displayed on the printers LCD.

    The printers firmware is still the same, I did download the Rpi image and do a fresh install as I recently overhauled my print enclosure adding a bunch of automation controlled with bash scripts called by Repetier, but the version number is still 0.80.2 so should still be the same unless a small fix has been pushed out in the current release?

    PS. Not complaining, just reporting this new behaviour.

  • I think it is the same problem as original reported problem. Prusa firmware reporting now A: making it ignore bed temperature for reading. Will be fixed in 0.90.0. So you can live with this as it does not affect printing in any way, or modify prusa firmware to not report A.
  • I had the same problem with Repetier-Host. Heated bed was not recognized. But removing the "A:" part in the M105 response did the trick.
  • @Dreide Can you share how you did this?

    Did you edit the config.h file and recompile the Firmware?
  • @iClint: I removed those two lines from Marlin_main.cpp and recompiled (Prusa firmware):

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