Extruder heating : keeps heating even when switching off …

WalterSKW

I have the following heater and tool defitions :

[[language]]
; Heaters
;
M305 P0 S"BED" T100000 B3950 C0 R4700 ; Set thermistor + ADC parameters 
M305 P1 S"Extruder" X200 ; Set PT100 for 1st extruder and connect to channel 200 (PT100)
; max temperatures
;M143 H1 S320 ; Hotend
;M143 H0 S140; Bed
; PID
M301 H0 S1.00 P127.4 I22.579 D123.6 T0.7 W150 B30 ; Use PID on bed heater 70% duty cycle
;
; Tools
; Define tool 0 = Extruder 0, Heater 1 
M563 P0 D0 H1 F1
G10 P0 X0 Y0 Z0 R0 S0; Set tool 0 axis offsets, tool 0 active and standby temperatures to 0C

Reporting with M305 gives the following :

[[language]]
9:46:56 PMM305 P0
Heater 0 (BED) uses Thermistor sensor channel 0, T:100000.0 B:3950.0 C:0.00e+00 R:4700.0 L:0 H:0
9:46:29 PMM305 P1
Heater 1 (Extruder) uses PT100 (MAX31865) sensor channel 200, reject 50Hz

```When I set the temperature of tool 0/heater 1 to let say 180°C, the heater starts, temperature increases but doesn't stop at 180°. Just continues… until I disconnnect the heater power connector.

[[language]]
9:56:48 PMM408 S1
{"status":"I","heaters":[29.5,197.2],"active":[0.0,180.0],"standby":[0.0,0.0],"hstat":[0,3],"pos":[0.000,0.000,0.000],"sfactor":100.00,"efactor":[100.00],"babystep":0.000,"tool":0,"probe":"0","fanPercent":[0.00,100.00,100.00,0.00,0.00,0.00,0.00,0.00,0.00],"fanRPM":0,"homed":[0,0,0],"msgBox.mode":-1,"geometry":"cartesian","axes":3,"volumes":2,"numTools":1,"myName":"My Duet","firmwareName":"RepRapFirmware for Duet WiFi"}

9:57:13 PMM408 S1
{"status":"I","heaters":[29.5,225.7],"active":[0.0,180.0],"standby":[0.0,0.0],"hstat":[0,3],"pos":[0.000,0.000,0.000],"sfactor":100.00,"efactor":[100.00],"babystep":0.000,"tool":0,"probe":"0","fanPercent":[0.00,100.00,100.00,0.00,0.00,0.00,0.00,0.00,0.00],"fanRPM":0,"homed":[0,0,0],"msgBox.mode":-1,"geometry":"cartesian","axes":3,"volumes":2,"numTools":1,"myName":"My Duet","firmwareName":"RepRapFirmware for Duet WiFi"}

9:57:38 PMM408 S1
{"status":"I","heaters":[29.4,251.0],"active":[0.0,180.0],"standby":[0.0,0.0],"hstat":[0,3],"pos":[0.000,0.000,0.000],"sfactor":100.00,"efactor":[100.00],"babystep":0.000,"tool":0,"probe":"0","fanPercent":[0.00,100.00,100.00,0.00,0.00,0.00,0.00,0.00,0.00],"fanRPM":0,"homed":[0,0,0],"msgBox.mode":-1,"geometry":"cartesian","axes":3,"volumes":2,"numTools":1,"myName":"My Duet","firmwareName":"RepRapFirmware for Duet WiFi"}

9:58:43 PMM408 S1
{"status":"I","heaters":[29.4,299.5],"active":[0.0,180.0],"standby":[0.0,0.0],"hstat":[0,3],"pos":[0.000,0.000,0.000],"sfactor":100.00,"efactor":[100.00],"babystep":0.000,"tool":0,"probe":"0","fanPercent":[0.00,100.00,100.00,0.00,0.00,0.00,0.00,0.00,0.00],"fanRPM":0,"homed":[0,0,0],"msgBox.mode":-1,"geometry":"cartesian","axes":3,"volumes":2,"numTools":1,"myName":"My Duet","firmwareName":"RepRapFirmware for Duet WiFi"}

I am missing something in the heater numbering or definitions I guess. Heater is physically connected to the E0 heater terminal.

Can someone show me the light? (Not a fire because of overheating ;) )

dc42

1. That M301 command is obsolete. You should run heater tuning and use M307 instead.

2. There is a bug with using named heaters in firmware 1.19 that might be related to what you observe. It is fixed in the 1.19.1 release candidate, available at https://www.dropbox.com/sh/wq0u70kpapqc3is/AAC6I8TS5Lbwuziq_r3M15Qea?dl=0. Please either upgrade, or don't use named heaters.

WalterSKW

to 1) Will change bed tuning PID params to M307 this evening. But this is about the bed and that works just fine.
to 2) I have version 1.19.+3 from dropbox installed. This test is done with that version.
I saw there is a +4 update available, will install that later today.

I suppose that my setup code is ok?
I use a 4wire PT100, since the temperature seems to follow the heating, this should be ok.
Since setting temperature and activating the heater also switches on the heater, I suppose that that definition and connection must be ok too.
It is the only issue I still have to start some printing.
Only extruder stepper to be tested after the heater test.

Everything moves nicely and superquiet, thermostatic fan setup is a dream.
I had TMC's before (Silentstepsticks from Watteroth), but this is just way better.
Everything runs on 24V, Bed is 230V/750W over a SSR.

WalterSKW

Upgraded to newest firmware

[[language]]
M122
=== Diagnostics ===
Used output buffers: 3 of 32 (12 max)
=== Platform ===
RepRapFirmware for Duet WiFi version 1.19+4 running on Duet WiFi 1.0
Board ID: 08DDM-9FAM2-LW4SD-6J9F2-3SD6P-K2W3X
Static ram used: 21176
Dynamic ram used: 95928
Recycled dynamic ram: 1680
Stack ram used: 1304 current, 4904 maximum
Never used ram: 7384
Last reset 00:03:35 ago, cause: power up
Last software reset reason: User, spinning module GCodes, available RAM 7240 bytes (slot 1)
Software reset code 0x0003, HFSR 0x00000000, CFSR 0x00000000, ICSR 0x00400000, BFAR 0xe000ed38, SP 0xffffffff
Error status: 0
Free file entries: 10
SD card 0 detected, interface speed: 20.0MBytes/sec
SD card longest block write time: 0.0ms
MCU temperature: min 37.9, current 40.4, max 40.6
Supply voltage: min 24.1, current 24.2, max 24.5, under voltage events: 0, over voltage events: 0
Driver 0: standstill
Driver 1: standstill
Driver 2: standstill
Driver 3: standstill
Driver 4: standstill
Date/time: 2017-08-29 17:19:20
Slowest main loop (seconds): 0.007545; fastest: 0.000033
=== Move ===
MaxReps: 0, StepErrors: 0, FreeDm: 240, MinFreeDm 240, MaxWait: 0ms, Underruns: 0, 0
Scheduled moves: 0, completed moves: 0
Bed compensation in use: none
Bed probe heights: 0.000 0.000 0.000 0.000 0.000
=== Heat ===
Bed heater = 0, chamber heater = -1
Heater 1 is on, I-accum = 0.4
=== GCodes ===
Segments left: 0
Stack records: 1 allocated, 0 in use
Movement lock held by null
http is idle in state(s) 0
telnet is idle in state(s) 0
file is idle in state(s) 0
serial is idle in state(s) 0
aux is idle in state(s) 0
daemon is idle in state(s) 0
queue is idle in state(s) 0
autopause is idle in state(s) 0
Code queue is empty.
Network state is running
WiFi module is connected to access point 
WiFi firmware version 1.19+1
WiFi MAC address 60:01:94:34:41:07
WiFi Vcc 3.14, reset reason Turned on by main processor
WiFi flash size 4194304, free heap 39080
WiFi IP address 192.168.0.250
WiFi signal strength -53dBm
HTTP sessions: 1 of 8
Socket states: 2 0 0 0 0 0 0 0
Responder states: HTTP(1) HTTP(0) HTTP(0) HTTP(0) FTP(0) Telnet(0)

Changed to this config for heaters :

[[language]]
; Heaters
;
M305 P0  T100000 B3950 C0 R4700 ; Set thermistor + ADC parameters 
M305 P1  X200 ; Set PT100 for 1st extruder and connect to channel 200 (PT100)
; max temperatures
M143 H1 S250 ; Hotend
M143 H0 S140; Bed
; PID
M307 H0 S0.7 B0 A90 C700 D10
M307 H1 S1.0 B0 A340 C140 D5.5
;
; Tools
; Define tool 0 = Extruder 0, Heater 1 
M563 P0 D0 H1 F1

Set target temperature to 180°C and activated heater.
The heater doesn't switch off and I have to unplug the heater connector. Goes beyond 300°C.
I get this error : Error: heating fault on heater 1, temperature excursion exceeded 15.0C

any thoughts?

WalterSKW

Found the issue:
I saw that as soon as the extruder fan started, the heater also started.
Switching off thermostatic mode and playing with on/off, the heater followed and also the fet controlling the heater.
During a close inspection of the cabling I saw that the fan wires had been damaged when mounting the printhead and made a contact somewhere with the heater indicator led pins on the PCB @ the printhead.
How this switched on the FET, i don't know yet.

Sorry for this…

dc42

Thanks for keeping us updated.