Heater fault - failed to read sensor

awitc

Hi!

I have a tool which has 6 heaters. All of them are configured in the same way for testing purposes, and only heater 4 is causing problems. When I set the heater active, this is what I get:

Even though the readings are correct*:

The rest is behaving as expected. I checked the wiring and it seems consistent for every heater.

I am using thermocouple boards with a J-type thermocouple in each heater.

My config:

; Default config.g template for DuetPi
; Replace this with a proper configuration file (e.g from https://configtool.reprapfirmware.org)

; General
G90								; absolute coordinates
M83								; relative extruder moves
G4 S2 							; wait for expansion boards to start

; set axis travel minima and maxima
M208 X0:480 Y0:480 Z0:500

; define mesh grid size and spacing
M557 X40:440 Y40:440 S40

; Driver configuration
M584 X0 Y1 Z2:3 E1.0				; assign drives to axes

M569 P0.0 R1 S0 T2.5:2.5:5:2.5		; sets the given drive to go: 0=backwards, 1=forwards
M569 P0.1 R1 S1 T2.5:2.5:5:2.5		; timings for min. step pulse, min. step interval, DIR setup time, hold time
M569 P0.2 R1 S1 T2.5:2.5:5:2.5		; R1 makes the drive to be enabled by HIGH
M569 P0.3 R1 S1 T2.5:2.5:5:2.5	
M569 P1.0 S1

M350 X32 Y32 Z32 E32 I0				; microstepping with/without interpolation
;M92 X20.65 Y20.65 Z800.00 E420 		; [steps/mm] for 16 microsteps
M92 X41.29 Y41.29 Z1600 E840 		; [steps/mm]

M566 X900.00 Y900.00 Z40.00 E120.00 	; maximum instantaneous speed changes [mm/min]
M203 X5400.00 Y5400.00 Z480.00 E600.00 	; maximum speeds [mm/min]
M201 X1000.00 Y1000.00 Z40.00 E250.00 	; accelerations [mm/s^2]

M906 X6000 Y6000 Z6000 E800 I30 		; motor current [mA], and motor idle factor [%]

; Thermocouple configuration
M308 S1 P"spi.cs1" Y"thermocouple-max31856" K"J"
M308 S2 P"spi.cs2" Y"thermocouple-max31856" K"J"
M308 S3 P"spi.cs3" Y"thermocouple-max31856" K"J"
M308 S4 P"spi.cs4" Y"thermocouple-max31856" K"J"
M308 S5 P"1.spi.cs0" Y"thermocouple-max31856" K"J"
M308 S6 P"1.spi.cs1" Y"thermocouple-max31856" K"J"

; M950 H1 C"out0" T1 	; maps to the previously created S1 (sensor 1)
; M307 H1 B0 S1.00		; disable bang-bang mode for heater 1, set pwm limit
; M143 H1 S200			; set temperature limit for heater 1

; Thermistor configuration
M308 S7 P"1.temp1" Y"thermistor" T100000 B4267 C7.06e-8 ; extruder
M308 S8 P"1.temp0" Y"thermistor" T100000 B4540 C7.06e-8 ; bed

; Heater configuration
;; heater 1
M950 H1 C"0.out0" T1
M307 H1 B0 S1.00
M143 H1 S50

;; heater 2
M950 H2 C"0.out1" T2
M307 H2 B0 S1.00
M143 H2 S50

;; heater 3
M950 H3 C"0.out2" T3
M307 H3 B0 S1.00
M143 H3 S50

;; heater 4
M950 H4 C"1.out0" T4
M307 H4 B0 S1.00
M143 H4 S50

;; heater 5
M950 H5 C"1.out1" T5
M307 H5 B0 S1.00
M143 H5 S50

;; heater 6
M950 H6 C"1.out2" T6
M307 H6 B0 S1.00
M143 H6 S50

;; bed
M950 H8 C"out6" T8
M307 H8 R0.341 K0.128:0.000 D16.03 E1.35 S1.00 B0
M143 H8 S110
M140 H8

;; extruder
M950 H7 C"0.out7" T7
M307 H7 B0 S1.00
M143 H7 S285

; Tools
M563 P0 D0 H7 F0 		; tool definition
G10 P0 X0 Y0 Z0			; tool axis offsets
G10 P0 R0 S0			; initial tool active and standby temperatures equal 0

M563 P1 D0 H1:2:3:4:5:6 S"Snail"
G10 P1 X0 Y0 Z0
G10 P1 R0 S0

; Endstop configuration
M574 X2 S1 P"io5.in.iso" 			; X1 stands for low end, 2 would be for high end
M574 Y1 S1 P"io6.in.iso" 			; S1 stands for switch type, 1 = microswitch

; Z Probe (BLTouch) configuration
M950 S0 C"io7.out"
M558 P9 C"io7.in" H5 F120 T6000
G31 X-31 Y-35 Z3.5 P25 	; -2.75			; Probe offsets, trigger height and trigger value

; accelerometer configuration
;M955 P0 C"io8.out+io8.in" Q500000				; CS and INT1 connected to IO8

Would it be something with the thermocouple board?

- on a side note, do the thermocouple readings tend to float or raise a bit over time? My readings should be around 22-23 'C, but they are a bit higher.

Looking forward to any feedback!

Best regards,
AW

awitc

From what I have figured out, the the thermocouple board was faulty. Even though it displays the temperature treading, whenever a heater tried to 'use' the sensor, it resulted in a fault. I used a spare terminal on an expansion board and it works.

dc42

@awitc assuming you purchased that thermocouple board from a genuine Duet3D reseller, please start a warranty claim by emailing warranty@duet3d.com. Include a link to this thread in your email and cc your supplier.