Problems with 24V inductive Sensor for endstop

Froschkönig

Hello community,

i have a Duet3d 6HC Mainboard and i try to upgrade my existing 3D printer.
I have inductive endstops on all 3 axis (https://de.farnell.com/panasonic/gx-f12b-p/sensor-4mm-pnp-nc-2m-kabel/dp/2357991).
The sensors are connected directly with my 24V power source and i wired only the signal wire to the input pin. When using a multimeter i measure correctly 24V and 0V depending of my axis, but the software is not reacting in any way.
The sensor is normally closed, so my config.g is M574 X1 S1 P"!io0.in". But i tried all other combinations aswell without any result.
Am i missing some electronic basics? (I'm more the mechanical guy...)

Maybe someone here can help me, would be great

Greetings
Frosch

alankilian

@Froschkönig What results do you get from the M119 command when your endstop voltage is both zero and +24 Volts at the input pin?

Froschkönig

My config is M574 X1 S1 P"!io0.in" and i get " X: - not stopped". I get the same result with a srewdriver on the sensor (24V gone and light off, sensor is working).

With M574 X1 S1 P"io0.in" i get "X: - at min endstop". Again with and without screwdriver...

dc42

@Froschkönig whereas an NPN-output sensor can be connected directly to an input pin on the Duet, a PNP-output sensor can't. See https://docs.duet3d.com/en/User_manual/Connecting_hardware/Z_probe_connecting#pnp-output-normally-open-inductive-or-capacitive-sensor. This isn't a Duet-specific thing, most 3D printer boards are like this.

Froschkönig

Thanks a lot guys, you were right (of course)

Sensor is now working like a charme
not sure how to set the topic as solved...