Multiple bed heater configuration problem

Lem

Hello!

I have a problem with two bed heaters on Duet 3 6HC.

; Left Nozzle
M308 S0 P"20.temp0" Y"pt1000" A"Left A"					; configure sensor 0 as thermistor on tool board board pin temp0
M308 S8 P"20.temp1" Y"pt1000" A"Left B"					; configure sensor 0 as thermistor on tool board board pin temp0
M950 H0 C"20.out0" T0							; create nozzle heater output on out0 and map it to sensor 0
M950 H8 C"20.out1" T8
M307 H0 R1.085 K0.153:0.000 D4.55 E1.35 S1.00 B0 V23.1	; PID parameters - tuning separetly
M307 H8 R1.085 K0.153:0.000 D4.55 E1.35 S1.00 B0 V23.1	; PID parameters - tuning separetly
M143 H0 S455								; set temperature limit for heater 0 to 455C
M143 H8 S455								; set temperature limit for heater 0 to 455C
M950 F0 C"!1.out7" Q10000						; configure fan 0, F = 10 kHz, PWM range from 0.3 to 1.0
M106 P0 S0
M563 P0 D0 H0:8                           				; 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

; Bed
M308 S2 P"0.temp0" Y"pt1000" A"Bed"			; configure sensor 2 as thermistor on pin temp0
M308 S3 P"0.temp1" Y"pt1000" A"Bed"			; configure sensor 3 as thermistor on pin temp1
M950 H2 C"0.out1" T2					; create bed heater output on out1 and map it to sensor 0
M950 H3 C"0.out2" T3					; create bed heater output on out1 and map it to sensor 0
M307 H2 B1 R0.05 D10 I1 V0				; configure heater 2 as bang-bang, 0*C/s heating rate, dead time 10 s, inverted signal
M307 H3 B1 R0.05 D10 I1 V0				; configure heater 3 as bang-bang, 0*C/s heating rate, dead time 10 s, inverted signal
M570 H2 P120 T100					; configure heater fault detection
M570 H3 P120 T100					; configure heater fault detection
M143 H2 S185
M143 H3 S185
M140 P0 H2 S0 R0					; map heated bed to heater 2	
M140 P1 H3 S0 R0					; map heated bed to heater 3

When it is configured as above - everything is ok. I can heat both zones separately, temperature readings are correct.
When I change M140 to:

M140 P0 H2:3

Then I have heater and temperature from left nozzle.
I try change definitions order in config but without success.
What can be a reason of that behavior? Make a mistake in configuration?

Phaedrux

@lem said in Multiple bed heater configuration problem:

M140 P0 H2:3

I don't think you can gan heaters together like that. You'd need to keep them defined separately. If you wanted to control them together you'd need to send individual commands as well.

Lem

@phaedrux Thank you for reply. Unfortunetly when I configure bed this way it will be more complicated to configure slicers.

Here DC says:
"Yes you need to have four of each of those commands to define four temperature sensors and four heaters. Then one M140 command to allocate those four heaters to the bed."

Maybe someone has defined multiple heaters for one bed?

Phaedrux

It's not hard to configure your slicer start gcode to control multiple heaters. The set temp for the bed from the slicer is available as a variable and you can use a placeholder to insert that variable where ever you want it.

Which slicer are you using?

A made up example would be

M140 P0 S{slicer bed temp}
M140 P1 S{slicer bed temp}
M140 P2 S{slicer bed temp}
M140 P3 S{slicer bed temp}

All 4 bed heaters would be set.

The slicer would insert the configured bed temp into the placeholder when the file is sliced and exported. The actual placeholder variable syntax varies between slicers.

Lem

@phaedrux I'm using Simplify. I add new one gcode in Python DSF which set temperature for all beds and replace M140.

But I still don't understand why it's impossible to configure multiheater bed. For extruders it works nice.