termistors



  • Hello I have the Duetwifi built into the UM2. Only the termistors are plugged into the borad - now both indicate wrong temperatures.

    what could that be?Bildschirmfoto 2019-12-28 um 14.57.28.png



  • post your config.g!



  • what thermistors does the um2 have?



  • @Veti said in termistors:

    what thermistors does the um2 have?

    don't UM2's use Thermocouples or have I remembered incorrectly (Highly possible)



  • @Dougal1957

    the config.g

    ; Configuration file for Duet WiFi (firmware version 2.03)
    ; executed by the firmware on start-up
    ;
    ; generated by RepRapFirmware Configuration Tool v2.1.4 on Sat Dec 28 2019 00:04:16 GMT+0100 (CET)

    ; General preferences
    G90 ; send absolute coordinates...
    M83 ; ...but relative extruder moves
    M550 P"My Printer" ; set printer name

    ; Network
    M552 S1 ; enable network
    M586 P0 S1 ; enable HTTP
    M586 P1 S0 ; disable FTP
    M586 P2 S0 ; disable Telnet

    ; Drives
    M569 P0 S1 ; physical drive 0 goes forwards
    M569 P1 S1 ; physical drive 1 goes forwards
    M569 P2 S0 ; physical drive 2 goes backwards
    M569 P3 S1 ; physical drive 3 goes forwards
    M584 X0 Y1 Z2 E3 ; set drive mapping
    M350 X256 Y256 Z256 E256 I0 ; configure microstepping without interpolation
    M92 X80.00 Y80.00 Z4000.00 E420.00 ; set steps per mm
    M566 X900.00 Y900.00 Z12.00 E120.00 ; set maximum instantaneous speed changes (mm/min)
    M203 X6000.00 Y6000.00 Z180.00 E1200.00 ; set maximum speeds (mm/min)
    M201 X500.00 Y500.00 Z20.00 E250.00 ; set accelerations (mm/s^2)
    M906 X800 Y800 Z800 E800 I30 ; set motor currents (mA) and motor idle factor in per cent
    M84 S30 ; Set idle timeout

    ; Axis Limits
    M208 X0 Y0 Z0 S1 ; set axis minima
    M208 X220 Y220 Z200 S0 ; set axis maxima

    ; Endstops
    M574 X1 Y1 Z1 S1 ; set active high endstops

    ; Z-Probe
    M558 P0 H5 F120 T6000 ; disable Z probe but set dive height, probe speed and travel speed
    M557 X15:215 Y15:195 S20 ; define mesh grid

    ; Heaters
    M305 P0 T100000 B4138 R4700 ; set thermistor + ADC parameters for heater 0
    M143 H0 S120 ; set temperature limit for heater 0 to 120C
    M305 P1 T100000 B4138 R4700 ; set thermistor + ADC parameters for heater 1
    M143 H1 S280 ; set temperature limit for heater 1 to 280C

    ; Fans
    M106 P0 S0 I0 F500 H-1 ; set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned off
    M106 P1 S1 I0 F500 H1 T45 ; set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned on

    ; Tools
    M563 P0 D0 H1 F0 ; define tool 0
    G10 P0 X0 Y0 Z0 ; set tool 0 axis offsets
    G10 P0 R0 S0 ; set initial tool 0 active and standby temperatures to 0C

    ; Custom settings are not defined



  • @Veti what thermistors does the um2 have?

    Is a UM2 +, the termistors have previously worked properly.



  • I have to make every connector for the Duet, but before the termistors do not work - it has no purpose.



  • IMG_1401.JPG IMG_1400.JPG

    Termistor for hotend and heating bed



  • What is the resistance of the sensor when disconnected from the board?

    What values have you found for the sensors?



  • From UM2 firmware, it seems they use PT100 instead of regular thermistors, both hotend and bed.




  • administrators

    @minimaxer said in termistors:

    @DocTrucker

    112k

    Are you sure you mean 112K, not 112 ohms?



  • oh sorry - 112 ohm


  • administrators

    @minimaxer said in termistors:

    oh sorry - 112 ohm

    In that case, @aidar is right, they are PT100 sensors, not thermistors. To use them with Duet you need the PT100 daughter board. One board handles two PT100 sensors.



  • Ok, I read it, the UM2 + has PT100 sensors and I need an extra board -: ((



  • @minimaxer wasn't able to get back online last night but suspected PT100 as I had the same issue when converting an Up Plus 2 for someone an age ago.

    Ok extra cost but the boards mount on Duets (post 0.6 or 0.8.5) with no extra hardware. PT100 are better sensors on many measures, but rely on a well shielded system. That said, if you are converting a machine like the ultimaker then shielding issues are likely already sorted, unless it is broken accidentally in the conversion.

    Just keep an eye out for impossible heat changes on the temp plot. In other words if there are sudden changes of 5-10C or more in reported temp in an instant then you have wiring or noise issues.


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