PID for dual heater

yuval

hi, im using 2 heaters for my hotend
ive defined them, and i can get them to heat up, im using one thermisitor
heaters setup:

M308 S1 P"temp1" Y"PT1000"
M950 H1 C"out1" T1
M950 H2 C"out2" T1

tool setup:
M563 P0 S"X" D0 H1:2 F0:2

now, i want to tune pid both of the heaters, but i can only tune one of them

when i send m303 h1:2 s220 i get error for some reason it try to tune heater 0(BED)

if i send m303 t0 s220 it only uses one heater

any ideas?

jay_s_uk

@yuval tune as a tool rather than a heater.
e.g. M303 T0 S220

yuval

@jay_s_uk i think you didnt read everything

"if i send m303 t0 s220 it only uses one heater"

jay_s_uk

@yuval ah sorry.
you could map 2 outputs to one heater instead.
M950 H1 C"out1+out2" T1

yuval

@jay_s_uk so you think i should map
heater 1 output out1+out2
heater 2 output the same? out1+out2

jay_s_uk

@yuval you would just need the 1 heater defined.

yuval

@jay_s_uk im not sure i understand what you mean sir

yuval

@jay_s_uk i want to use 2 heaters, i have one thermisitor, im trying to PID tune using both

jay_s_uk

@yuval you use the M950 i posted above to define both outputs as one "heater" in the firmware then tune as normal

droftarts

@yuval said in PID for dual heater:

if i send m303 t0 s220 it only uses one heater

You should be able to set up the heaters as in your first post. Tuning them as a tool, with M303 should also work. How do you know only one heater was working? Make sure any heater faults are cleared before tuning.

In case this is a bug, and M303 isn't working correctly when a tool has more than one heater, please post what version of RepRapFirmware you are using; send M115 and post the response. Posting your full config.g would also help.

Ian

droftarts

@yuval said in PID for dual heater:

@jay_s_uk im not sure i understand what you mean sir

In case you want to try @jay_s_uk's suggestion, try:

M308 S1 P"temp1" Y"PT1000"
M950 H1 C"out1+out2" T1

;tool setup:
M563 P0 S"X" D0 H1 F0:2

Edit: note that multiple outputs for a single heater only works in RRF 3.4 and later.

M303 tuning should work in either way, M303 H1 S220 or M303 T0 S220, though usually best to tune as a tool.

Ian

yuval

@droftarts
i can see that only one heater is active, therfore i guess its only using one.
im using firmware 3.3, and havent changed anything yet(you can see in the post the way i defined the heaters)

jay_s_uk

@yuval in that case my suggestion won't work as it only came in as part of RRF3.4.0

droftarts

@yuval If you have tested both heaters independently, and they work, please swap the heaters around in the tool definition, and see if it heats up the other tool using M303. eg use M563 P0 S"X" D0 H2:1 F0:2 then M303 T0 S220. It may be a bug in M303 that only uses the first heater for tuning, though I would have thought this would have been discovered earlier.

Ian

yuval

@droftarts i will try.
but i think i prefer anyway to set both heaters to one, as i would never need to set different temps between the two heaters

droftarts

@yuval said in PID for dual heater:

@droftarts i will try.
but i think i prefer anyway to set both heaters to one, as i would never need to set different temps between the two heaters

Okay, then you'll need to update to RRF 3.4.5.

Ian

yuval

@droftarts ok sorry, my mistake, im running 3.4.5
i have idex, both 2 heaters
the 4th heater is connected to extansion board, and i get error
both heaters should be from the main board for some reason..

droftarts

@yuval said in PID for dual heater:

both heaters should be from the main board for some reason

That's a safety precaution, and a permanent limitation of RRF. See https://docs.duet3d.com/en/User_manual/RepRapFirmware/CAN_limitations#permanent-limitations

A heater on an expansion or tool board can only be controlled by a temperature sensor on the same expansion board. This is a safety precaution, because it ensures that temperature control is maintained even if CAN communication is lost.

Ian