Heater 1 reading 2000.0 °C

[DiegoSuarez]

Hello everyone,

I have problems with the PT100 from my Heater 1. It has been reading 2000°C and I have tried some of the previous solutions in this forum but with no success yet.

I am using a Duet 2 WiFi/Ethernet board and a RRF version 2.03. Also using the TP100 daughterboard. I used the 100Ω resistance on the TP100 cables and is giving me -1.5 (close to 0, which I think is good). I tried with two different PT100 thermistors, a 300°C one and a 500°C one with the respective config.g changes, but couldn't get it. The 300°C resistance reads 103KΩ and the 500 reds 4MΩ (so I think both work).

These are my 300°C lines:

; Heaters
M307 H0 B0 S1.00 ; Disable bang-bang mode for the bed heater and set PWM limit
M305 P0 T100000 B4138 C0 R4700 ; Set thermistor + ADC parameters for heater 0
M143 H0 S115 ; Set temperature limit for heater 0 to 110C
M305 P1 X200 S0.55 ; PT100 Chanel 1
M143 H1 S295 ; Set temp limit for heater 1
M570 H1 P20 T25 ; Adjust heater parameters - 10-second threshold over 25C

500°C lines:

; Heaters
M307 H0 B0 S1.00
M305 P0 T100000 B4138 C0 R4700
M143 H0 S115
M305 P1 R4700 H0 L0
M305 P1 T4606017 B5848 C5.548428e-8 R4700 H0 L0
M307 H1 A580.4 C256.6 D6.4 S0.50
M143 H1 S493
M570 H1 P20 T25

Can anyone help me figure it out? I really would appreciate it. Thank you!

[chrishamm]

@DiegoSuarez Upgrade to firmware and web interface versions 3.4.6 and then continue troubleshooting. Version 2 is really old and we don't really support that any more. Please see https://docs.duet3d.com/en/User_manual/RepRapFirmware/Migration_RRF2_to_RRF3 and then continue troubleshooting.

[dc42]

@DiegoSuarez said in Heater 1 reading 2000.0 °C:

The 300°C resistance reads 103KΩ and the 500 reds 4MΩ (so I think both work).

Those are not PT100 sensors, they are thermistors.

[Zoltan3D]

@DiegoSuarez 2000°C ?

Wow congratulations, you are able to print Aluminium, iron, steel and even Titanium XD

Sorry, I don't resisted to do this joke

[DiegoSuarez]

Hello, @chrishamm and @dc42

I updated the firmware 3.4.6 version. Also updated my config.g file parameters.
But I have a couple of troubles. First, Heater 1 is still not reading correctly. It is reading -273.1 C with or without the thermistor connected. The thermistor does work, it has a 110KΩ resistance at room temperature.

; HotEnd
M308 S1 P"e0temp" Y"thermistor" T100000 B4680 C6.455513e-8
M950 H1 C"e0heat" T1
M307 H1 A216.0 C139.3 D1.0 S0.57 V24.3 B0 ; Disable bang-bang for heater and set PWM limit
M143 H1 S300 ; Set temp limit for heater 1

2nd problem: The interface is no longer reading anything, is a PanelDue 7i. It turns on as always but won't send a command to the printer, nor read temperatures or coordinates.

I appreciate the help!

[droftarts]

@DiegoSuarez See https://docs.duet3d.com/en/How_to_guides/Commissioning#h-4-check-thermistors

If you get a temperature reading of "-273°C", this indicates an open circuit, i.e. nothing is connected to the defined pins.

• Check that the temperature sensor is connected to the correct pins
• Check the wiring for breaks
• Measure the resistance of the wires that connect to the Duet, and that it corresponds with what the firmware expects
• Check that the configuration is set correctly for the temperature sensor.

If you're using the same thermistor for bed and hot end, plug the bed thermistor wire into e0temp to test if the temperature reads correctly.

Or put a 100k ohm resistor on e0temp pins. I have these for testing:

Ian

[Phaedrux]

@DiegoSuarez said in Heater 1 reading 2000.0 °C:

The interface is no longer reading anything, is a PanelDue 7i.

You're likely missing the command needed to enable the paneldue required in the 3.x firmware.

M575 P1 B57600 S1
https://docs.duet3d.com/User_manual/Reference/Gcodes#m575-set-serial-comms-parameters

[DiegoSuarez]

@Phaedrux this helped with the Paneldue thanks!

I still have problems with the heater 1, though. It is no longer reading -273, but it returned to 2000 °C. Connecting a 100Ω resistor, it reads -1.5°C. My wiring looks ok, and I have tried different things on my config.g, but I can not get it right. My PT100 thermistor has a 108KΩ resistance at room temperature.

This is my config.g of the H1
; HotEnd
M308 S1 P"spi.cs1" Y"rtd-max31865" ; configure sensor 1 as PT100 on pin spi.cs1
M950 H1 C"e0heat" T1 ; create heater and map sensor 1
M307 H1 B0 S1.00 ; disable bang-bang mode for heater and set PWM limit
M143 H1 S295 ; set temperature limit for heater 1 to 295C

Sorry for the inconvenience, could anyone help me here? Thanks in advance!

[droftarts]

@DiegoSuarez said in Heater 1 reading 2000.0 °C:

My PT100 thermistor has a 108KΩ resistance at room temperature.

Are you sure you measure 108 kiloohms, 108,000 ohms? If so, that's not a sensible reading for a PT100, see this resistance table: https://www.sterlingsensors.co.uk/pt100-resistance-table
That's more like a 100k ohm thermistor. You said in your first post:

I tried with two different PT100 thermistors, a 300°C one and a 500°C one

Thermistors plug directly into the temperature inputs on the board. You can't use them with the PT100 daughterboard.

Ian

[DiegoSuarez]

You're right, @droftarts! I was told it was a PT100 but in reality is a 100k thermistor. Now is finally reading well! Thank you!!