Anyone know why I wouldn't be able to turn 4-wire fans off?



  • Hi.

    I have connected 3st 4 wire PWM fans to a duet 3 and got used to get the RPM value to show up (mostly correct).
    But I am completely unable to turn them off.
    I can turn them down to 10% speed and then the RPM go from 1300 to 700 (min for the fans should be 300).
    But I am completely unable to turn them off M106 S0 just set them to 100%.

    Anyone have any Ideas? I am getting a bit mad from this and I am sure is something simple I just haven't thought of but I can't find anyone having the same issue.

    I tried to upgrade from the v3 alpha I was running but the only effect that had was that I first got a truly unpleasant web interface that didn't have the possibility to show rpm and when I downgraded to 1.22.5 it have the feeld to show rpm but only show it for a second each time I run M106.

    config (3).g


  • administrators

    The Intel specification for PWM fans doesn't require them to turn off completely, only to go down to 30% speed or lower.

    Noctua 4-wire fans do turn off at zero PWM.



  • @Axel-H I find that dwc 2.07 only shows rpm briefly too, when I change the setting.


  • administrators

    @Adrian52 said in Anyone know why I wouldn't be able to turn 4-wire fans off?:

    @Axel-H I find that dwc 2.07 only shows rpm briefly too, when I change the setting.

    Which version of RepRapFirmware are you using?

    When the fan RPMs are not displaying, please send M408 S2 and see whether the "fanRPM" part of the response shows sensible values or the values are all -1. That will show whether RRF is reporting the fan RPMs to DWC.



  • @dc42 I get -1,-1,-1 for the fan section of the M408 S2 response, running 3.01rc1, whether the rpm-able fan is running or not. The briefly displayed rpm when adjusting fan slider seems sensible.


  • administrators

    @Adrian52 said in Anyone know why I wouldn't be able to turn 4-wire fans off?:

    @dc42 I get -1,-1,-1 for the fan section of the M408 S2 response, running 3.01rc1, whether the rpm-able fan is running or not. The briefly displayed rpm when adjusting fan slider seems sensible.

    What type of fan is it, and how have you connected it to the Duet?



  • @dc42 Its a 60mm 4 wire noctua I use for manual extra cooling. The fans are configured:

    M106 P0 S0 H-1                                      ; set fan 0 value. Thermostatic control is turned off
    M950 F1 C"fan1" Q500                                ; create fan 1 on pin fan1 and set its frequency
    M106 P1 S1 H1 T45                                   ; set fan 1 value. Thermostatic control is turned on
    M950 F2 C"!Fan2+^exp.pb6" Q25000
    M106 P2 S0 H-1 C"Extra cool"
    

    The 4 wire fan has black and yellow to an always on fan header, blue to fan2 -ve(PWM) and green to pb6 on the extension header(RPM).


  • administrators

    @Adrian52 said in Anyone know why I wouldn't be able to turn 4-wire fans off?:

    @dc42 Its a 60mm 4 wire noctua I use for manual extra cooling. The fans are configured:

    M106 P0 S0 H-1                                      ; set fan 0 value. Thermostatic control is turned off
    M950 F1 C"fan1" Q500                                ; create fan 1 on pin fan1 and set its frequency
    M106 P1 S1 H1 T45                                   ; set fan 1 value. Thermostatic control is turned on
    M950 F2 C"!Fan2+^exp.pb6" Q25000
    M106 P2 S0 H-1 C"Extra cool"
    

    The 4 wire fan has black and yellow to an always on fan header, blue to fan2 -ve(PWM) and green to pb6 on the extension header(RPM).

    Odd, I was sure that Noctua had told me that all their PWM fans went down to zero speed. My 40mm Noctua fan does. OTOH the Arctic F12 fans that I have don't turn off, they do down to about 30%.



  • @dc42 Sorry my noctua does go down to zero. My issue was that rpm only shows briefly then disappears, as mentioned by the op



  • @Adrian52 said in Anyone know why I wouldn't be able to turn 4-wire fans off?:

    s that rpm only shows briefly then disappears, as mentioned by the op

    I get this form M408 S2:

    {"status":"I","coords":{"axesHomed":[0,0,0],"wpl":1,"xyz":[10.000,125.000,200.000],"machine":[10.000,125.000,200.000],"extr":[78948.0]},"speeds":{"requested":0.0,"top":0.0},"currentTool":-1,"params":{"atxPower":1,"fanPercent":[100,0,0,0,100,0],"speedFactor":100.0,"extrFactors":[100.0],"babystep":0.000},"sensors":{"probeValue":0,"fanRPM":[-1,-1,-1,-1,-1,-1]},"temps":{"chamber":{"current":22.9,"active":0.0,"state":0,"heater":0},"current":[22.9,22.7],"state":[0,1],"tools":{"active":[[210.0]],"standby":[[0.0]]},"extra":[]},"time":212261.0}
    

    Still only "fanRPM":[-1,-1,-1,-1,-1,-1]

    Version

    Firmware: RepRapFirmware for Duet 3 MB6HC v0.6 or 1.0 3.0 (2020-01-03b3) ```
    
    I would really appreciate being able to just cut the power (or the gnd return) for out4-out6 if that is possible, as I am a bit limited in what manufacturers fan I need to connect to them and I need sometime need them to be off.


  • I also get my edits flagged as spam all the time when I try to clean stuff upp10ed126d-40c7-4936-9c30-c78b33dfc709-image.png


  • administrators

    @Adrian52 said in Anyone know why I wouldn't be able to turn 4-wire fans off?:

    @dc42 Sorry my noctua does go down to zero. My issue was that rpm only shows briefly then disappears, as mentioned by the op

    I confirm that fault (RPM only showing briefly). I have just fixed it in the forthcoming 3.01-RC2.



  • Thank you.
    Do it exist any way to get the RPM to show up in the new webcontroller GUI or are it hidden because it showed -1?


  • administrators

    @Axel-H said in Anyone know why I wouldn't be able to turn 4-wire fans off?:

    Thank you.
    Do it exist any way to get the RPM to show up in the new webcontroller GUI or are it hidden because it showed -1?

    It's hidden because RRF is reporting -1.

    If you wish, you can try the internal RRF build at https://www.dropbox.com/sh/3azy1njy3ayjsbp/AACquxr2m00eV568RZg5QG5wa?dl=0 which includes the fix. There have been changes to some commands since 3.01-RC1, see https://github.com/dc42/RepRapFirmware/blob/v3-dev/WHATS_NEW_RRF3.md for details.



  • Thanks.

    Any idea if it might be possible to shut down the power to/from the fan it they are form a maker that don't shut them down completely or if someone have to use the out and gnd pins of the 4 pin connections to control "regular" fans?


  • administrators

    @Axel-H said in Anyone know why I wouldn't be able to turn 4-wire fans off?:

    Thanks.

    Any idea if it might be possible to shut down the power to/from the fan it they are form a maker that don't shut them down completely or if someone have to use the out and gnd pins of the 4 pin connections to control "regular" fans?

    It would require 2 mosfets to control the fan, one to control the PWM signal and one to shut off the power. I guess you could use two fan outputs to do that, but then you would need two M106 commands to control the fan: one to turn it on and off, and one to control the speed. The simple option is to get a Noctua fan instead. Alternatively, see if it works in regular 2-wire PWM mode. If so, you can connect the tacho wire as well, but it will read correctly only when running at full speed.



  • Thank you for all the help.

    Turning the fans off works as you said with noctua fans.

    But turning of out4-out6 even when set to work as regular fans don't seem to work though.

    Edit:
    I thought I got some odd values on the tachometer as I use rather long cables but apparently noctuas 40mm fans are supposed to go at 5000 rpm


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