@alankilian Thank you that picture. It seems at one point I reversed the direction of the idler. I am getting an short green flash with a long red flash now. When I move filament thru it it becomes green. I will try to test with it shortly and see if that does it.

@dommilan Not sure what happened, bit M591 D0 now returns: Error: M591: Driver 2.2 has no filament monitor

@jay_s_uk Unfortunately that had no effect of the issue. Here is my new pin assignment for my filament sensor.
M591 D0 P1 C"2.io0.in" S1

So I am trying to configure a simple switch sensor to a 6HC (that has a expansion board attached)

I have configured my sensor as such
; Filament Sensor
M591 D0 P1 C"io4.in" S1

But the console returns this after sending M591 D0
M591 D0
Extruder 0 has no filament sensor

No M591 commands in my overide.g

Attached is my config.g

; Configuration file for Duet3 Mini5+ with Mini2+ expansion (firmware version 3.3 or newer)
; executed by the firmware on start-up

; General preferences
M111 S0 ; Debugging off
G21 ; Work in millimetres
G90 ; Send absolute coordinates...
M83 ; ...but relative extruder moves

M669 K1 ; Select CoreXY mode
M564 S1 H1 ; Forbid axis movements when not homed
M575 P1 S1 B57600;
;M564 H0 S0
; Network
M550 P"Ray's Voron" ; Set machine name
M552 S1 ; Enable network
M586 P0 S1 ; Enable HTTP (for DWC)
M586 P1 S1 ; Enable FTP (for remote backups)
M586 P2 S0 ; Disable Telnet

; --- Z Drive map ---
; _______
; | 1 | 2 |
; | ----- |
; | 0 | 3 |
; -------
; front
;
; (looking at the printer from the top)

; Drive directions
M569 P2.0 S1 ; physical drive 1.0 goes forwards
M569 P2.1 S0 ; physical drive 1.1 goes forwards
M569 P0.0 S0 ; physical drive 0.0 goes forwards
M569 P0.1 S0 ; physical drive 0.0 goes forwards
M569 P0.2 S0 ; physical drive 0.0 goes forwards
M569 P0.3 S1 ; physical drive 0.0 goes forwards
M569 P2.2 S0 ; physical drive 1.2 goes forwards

; Motor mapping and steps per mm
M584 X2.0 Y2.1 Z0.0:0.1:0.2:0.3 E2.2
M350 X16 Y16 I1
M350 Z16 E16 I1 ; Use 1/16 microstepping with interpolation everywhere

M92 X80 Y80 Z400 ; Set XYZ steps per mm (1.8deg motors)
;M92 X160 Y160 Z400 ; Set XYZ steps per mm (0.9deg motors)
M92 425.13 ; Set Extruder steps per mm

; Drive currents
M906 X1500 Y1500 Z1200 E800 ; XYZ and E current
M906 I30 ; Idle current percentage
M84 S120 ; Idle timeout

; Accelerations and speed
M98 P"/macros/print_scripts/setup_printing.g"

; Axis travel limits
M208 X0 Y0 Z0 S1 ; Set axis minima
M208 X350 Y357 Z325 S0 ; Set axis maxima

; Endstops
M574 X2 S1 P"^io1.in" ; Xmax endstop on hall effect board
M574 Y2 S1 P"^io2.in" ; Ymax endstop on hall effect board
M574 Z0 S1 P"nil" ; No Z endstop

; Filament Sensor
M591 D0 P1 C"io4.in" S1

;M955 P0 C"spi.cs3+spi.cs4" I65

; Z probes
M558 K0 P8 C"^io5.in" T18000 F400 H5 A5 S0.01 R0.2
G31 K0 P500 X0 Y25 Z0 ; Don't really care about inductive probe Z offset
M558 K1 P8 C"^io3.in" T18000 F400:60 H2 A10 S0.005 R0.2
G31 K1 P500 X0 Y0 Z-0.21 ; Z switch offset (if positive, greater value = lower nozzle. if negative, more negative = higher nozzle)

; Bed leveling
M671 X-65:-65:365:365 Y0:395:395:0 S20 ; Define Z belts locations (Front_Left, Back_Left, Back_Right, Front_Right)
M557 X25:275 Y25:275 S25 ; Define bed mesh grid (inductive probe, positions include the Y offset!)

; Heaters

;HE0
M308 S1 P"temp0" Y"thermistor" T100000 B4725 C7.06e-8 ; configure sensor 0 as thermistor on pin temp0
M950 H1 C"out1" T1 ; create nozzle heater output on out1 and map it to sensor 0
M307 H1 B0 S1.00 ; disable bang-bang mode for heater and set PWM limit
M143 H1 S280 ; set temperature limit for heater 0 to 280C

; Bed heater
M308 S2 P"temp2" Y"thermistor" T100000 B3950 ; configure sensor 0 as thermistor on pin temp0 (heater sensor)
M950 H0 C"out2" T2 Q10 ; create bed heater output on out2 and map it to sensor 2 (mic6 sensor). Set PWM frequency to 10Hz
M140 P0 H0 ; Mark heater H0 as bed heater (for DWC)
M143 H0 S120 ; Set bed heater max temperature to 110°C, use implict monitor 0 which is implicitly configured for heater fault
M307 H0 B0 S0.6 ; disable bang-bang mode and set PWM to 60% to avoid warping
M570 H0 P400 T15

;CHAMBER TEMP
M308 S3 P"temp1" Y"thermistor" T100000 B4138 ; configure sensor 1 as thermistor on pin e1temp
M950 H2 C"out8" T3 ; create chamber heater output on e1heat and map it to sensor 2
M307 H2 B0 S1.00 ; disable bang-bang mode for the chamber heater and set PWM limit
M141 H2 ; map chamber to heater 2
M143 H2 S100 ; set temperature limit for heater 2 to 100C

; Fans
;HE FAN
M950 F0 C"out4" Q20 ; Create fan 0 (hotend) on pin out3 and set its frequency
M106 P0 S1 H1 T50 C"Hotend" ; Configure fan 0: Thermostatic control is turned on, based on sensor #1

;PART FAN
M950 F1 C"out3" Q20 ; Create fan 1 (cooling) on pin out4 and set its frequency
M106 P1 S0 H-1 C"Cooling" ; Configure fan 1: Thermostatic control is turned off

;E BAY FAN
M950 F2 C"out6" Q500 ; create fan 3 on pin out6 and set its frequency
M106 P2 C"E Bay" S1 H-1 ; set fan 3 name and value. Thermostatic control is turned off

;CHAMBER FAN
M950 F4 C"out5" Q500 ; Create fan 3 (chamber) on pin out6 and set its frequency
M106 P4 S1 H3 T55 C"Chamber" ; (temporary manual setup)

; LEDs
M950 F5 C"2.out3" ; Create fan 4 (top leds) on pin out2
M106 P5 S255 B0 H-1 C"Top Lights"

; Tools
M563 P0 D0 H1 F1 ; Define tool 0 using fan 1 for M106
G10 P0 X0 Y0 Z0 ; Set tool 0 axis offsets
G10 P0 R0 S0 ; Set initial tool 0 active and standby temperatures to 0C

; Misc
;M572 D0 S0.02 ; PLA PA
;M592 D0 A0.015 B0.0012 L0.2 ; Non-linear extrusion
M376 H3 ; Fade mesh out compensation over 10mm Z
;M912 P0 S-8.5 ; MCU temp calibration

; DAA tuning (you will need to change this for your slicer)
;M593 F35. ; Cura 4.5 stock profile @ 40mm/s outer printing speed
;M593 F42.5 ; PrusaSlicer @ 40mm/s outer perimeter

M80 ; turn on PSU & mains voltage

; set default LCD color
M150 X2 R100 U80 B255 P250 S3

M501 ; load config-override.g
T0 ; select tool 0

@alankilian I have it right before the extruder, I am trying to avoid placing it in line between the Hotend and Extruder as I have had issues with that with the BTT smart F sensor on my other machines. Changing the sensitivity seemed to do it. I was able to print with it. Sensitivity can be adjusted later should it be too weak. My esteps look good so I have my doubts about that being a root cause. I am happy with the progress made on this now. Took me a year to figure out what we did in these few days. Ill play with the settings but the root issue has been solved.

Thanks so much!

@alankilian
M591 D0 returns:
Duet3D magnetic filament monitor on input 3, enabled, sensitivity 24.80mm/rev, allow 70% to 130%, check every 3.0mm, version 3, mag 132 agc 108, measured sensitivity 26.31mm/rev, min 53% max 106% over 100.2mm

I am using this on a Tevo Little Monster with a real e3D Titan Extruder.

@alankilian It works when I am printing but whenever I get retractions it goes into a pause state.

@alankilian Thank you that picture. It seems at one point I reversed the direction of the idler. I am getting an short green flash with a long red flash now. When I move filament thru it it becomes green. I will try to test with it shortly and see if that does it.

@alankilian That did not resolve the issue

@alankilian

Long bolts are as tight as they will go.

This came with the plastic housing. I did see this documentation but they do not go into detail on how to solve this.