Simple Filament Sensor strange error

2500ccm

I have 5 simple filament runout sensors. All are same wired. All same configurated.
They goes to Duex5 E2 Stop to E5 Stop. Connected at Zstop and GND. STOPV is not connected. All Switches are working fine. But Switch 4 says all the time that filament is present. When i touch the switch the led on the board is on and off.
Maybe the pullup resistor is broken?`

Thanks for help! Nice forum

T3P3Tony

@2500ccm try swapping that particular switch with one that is working.

2500ccm

@T3P3Tony Disconnected Sensor 3 and 4. 3 - no filament. 4 - filament present. Switching both sensors: 4 - filament present

T3P3Tony

@2500ccm sorry can you be clearer, did the reading that's incorrect move with the switch or stay on the same channel on the Duet?

2500ccm

@T3P3Tony I have 5 sensors for filament present. duex.e5stop is the problem. It is tool4. This is my config.

; Filament endstops
M591 D0 P0
M591 D1 P2 C"duex.e2stop" S1
M591 D2 P2 C"duex.e3stop" S1
M591 D3 P2 C"duex.e4stop" S1
M591 D4 P2 C"duex.e5stop" S1
M591 D5 P2 C"duex.e6stop" S1

With M591 D0 to D5 i can see if filament present or not. When i disconnect cable at the sensor always it said: no filament present.
At tool4 / duex.e5stop it said with no cable connected at sensor: filament present.
When i switch cables from tool4 to another on, always filament present.
When i disconnect it from the board: filament present.

When the sensor is connected and i activate and deactivate the switch, the led on the board is going on and off.

2500ccm

@2500ccm I think the pullup resistor is maybe broken?`

T3P3Tony

@2500ccm ok, thanks, so the issue is with the channel on the board. When and where did you get the Duex 5? Also can you send a clear picture of the board from above so we can have a look.

The pullup resistor is R15

1K

its here on the board

So you can check it if you have a multimeter.

2500ccm

@T3P3Tony Filafarm germany. 15.02.2021
A clear photo is not that easy. I had nearly all sockets connected

2500ccm

@T3P3Tony Resistor have 1kohm

T3P3Tony

@2500ccm ok so it could be the LED, or some fault with the wiring between the Duex and the Duet or could be the processor on the Duet itself.

I wonder if that filament sensor could have picked up a static discharge from the filament .