Thermocouple Error Duet 3 Mini 5+ and 1LC

RogerPodacter

I just installed the thermocouple daughter board on the Duet 3 Mini 5+, and i cannot seem to configure the sensor correctly. The sensor reads normally and heats up reading correctly when reading normally in the chamber. But as soon as i go to use it in the hotend, i get immediate errors when heating up the hotend.

Heater fault
Heater 1 fault: failed to read sensor: unknown sensor

My config.g is as follows. the current 300C thermistor works fine, and was replaced with the Type K thermocouple which suddenly gives an error. Note the thermisor runs off the Toolboard 1LC, and the new TC now runs off of the mainboard thermocouple board. I dont think this should matter though.

M308 S1 P"121.temp0" Y"thermistor" T100000 B4725 C7.060000e-8 A"Slice Hotend"  ;Slice Engineering 300C thermistor, settings are online
M950 H1 C"121.out0" T1 Q100													; Define Heater1 as Extruder0 heater, bind to Sensor1
M307 H1 R3.030 K0.444:0.000 D4.49 E1.35 S1.00 B0 V23.8					; PID Tuning for Heater1, Extruder0 (240C)
M143 H1 S325														; Set temperature limit for heater 1 to 285C

If i replace M308 above with this new line, i get an error.

M308 S1 P"spi.cs1"Y"thermocouple-max31856" K"K" A"TC0 Slice Hotend"; define temperature sensor number 1 as a K Type thermocouple

jay_s_uk

@RogerPodacter you can't have a temp sensor on a different board to the heater cartridge https://docs.duet3d.com/en/User_manual/RepRapFirmware/CAN_limitations#permanent-limitations

RogerPodacter

@jay_s_uk Thats unfortunate, i now struggle to think of situations where a Toolboard 1LC and thermocouple daughterboard would ever be used together.

jay_s_uk

@RogerPodacter they won't. A 1LC is limited to thermistors and PT1000s

RogerPodacter

@jay_s_uk so my original goal i purchased a thermocouple duaghterboard to use hotter temperatures on my hotend for high temp materials. Anyone have suggestions what else i could use 2 thermocouples for in a CoreXY printer?

maybe i can put one directly on the heater fins to read chamber temperature. i dont want to "waste" using 2 highly capable TC's, but i am out of ideas.

jay_s_uk

@RogerPodacter not much I can think of for where you could put it to use. Maybe as a secondary bed temperature sensor?