Inductive Limit and Homing Switch

Hello, i have the following problem.
I have switched from mechanical limit switches to inductive ones.
I have 3 inputs reserved for the 3 axis and i have tried to connect the limits and the homing-signal to that pins.
when i now start homing the machine is moving to the switch and stops with a error "Referenzfahrt Fehler 14" in german (cant really translate the error because i dont know how to switch the language in linuxcnc-gui)
When i disconnect the neg and pos-signals from the switch, homing is working as expected.

Any hint what the failure is? the mechanical switches worked like a charm...

HAL-FILE:

net both-home-x <= lcec.0.1.din-3
net both-home-y <= lcec.0.1.din-1
net both-home-z <= lcec.0.1.din-2
net both-home-x => axis.0.home-sw-in
net both-home-x => axis.0.neg-lim-sw-in
net both-home-x => axis.0.pos-lim-sw-in
net both-home-y => axis.1.home-sw-in
net both-home-y => axis.1.neg-lim-sw-in
net both-home-y => axis.1.pos-lim-sw-in
net both-home-z => axis.2.home-sw-in
net both-home-z => axis.2.neg-lim-sw-in
net both-home-z => axis.2.pos-lim-sw-in

INI-FILE

[AXIS_0]
TYPE = LINEAR
HOME = 0.0
MAX_VELOCITY = 30.0
MAX_ACCELERATION = 1200.0
STEPGEN_MAXACCEL = 1500.0
SCALE = 200.0
FERROR = 1
MIN_FERROR = .25
MIN_LIMIT = -10.0
MAX_LIMIT = 300.0
HOME_OFFSET = -5.0
HOME_SEARCH_VEL = -20
HOME_LATCH_VEL = 7
HOME_SEQUENCE = 1
HOME_SWITCH_LOCATION = -10


[AXIS_1]
TYPE = LINEAR
HOME = 0.0
MAX_VELOCITY = 50.0
MAX_ACCELERATION = 1200.0
STEPGEN_MAXACCEL = 1500.0
SCALE = 200.0
FERROR = 1
MIN_FERROR = .25
MIN_LIMIT = -10
MAX_LIMIT = 450.0
HOME_OFFSET = -10.0
HOME_SEARCH_VEL = -20
HOME_LATCH_VEL = 5
HOME_SEQUENCE = 1

[AXIS_2]
TYPE = LINEAR
HOME = 0.0
MAX_VELOCITY = 60.0
MAX_ACCELERATION = 1200.0
STEPGEN_MAXACCEL = 1500.0
SCALE = 400.0
FERROR = 1
MIN_FERROR = .25
MIN_LIMIT = -100.0
MAX_LIMIT = 0.001
HOME_OFFSET= 5
HOME_SEARCH_VEL = 20
HOME_LATCH_VEL = -11.00
HOME_SEQUENCE = 0
BACKLASH = 0.025

now start homing the machine is moving to the switch and stops with a error "Referenzfahrt Fehler 14" in german (cant really translate the error because i dont know how to switch the language in linuxcnc-gui)

It just means "Homing Error 14" which is not instructive.

My first thought would be the wiring and HAL connection of the inductive sensors.

They often do not work in the way you might think, there are NPN and PNP variants and it is quite possible that the signal you are expecting is actually inverted from the one you used to get from your mechanical switches.
eg. it may be effectively NC and actually cease giving a signal when the void edge or whatever comes into range

Rather than testing homing, make sure they function properly as limits first, so you know what output to expect and go from there, checking that your original parport connections were not inverted, so you are getting a true picture.

regards

I have the PNP. They are setting the pin to active HIGH when the are triggered.
I will try out if they are working as limitswitch in the afternoon.
I dont use the parallel-port. I use ethercat for input and output-pins.
Only the step-generator for the stepper-drives are running via lpt-breakout.

invert the sense of the proximity switch in your hal file
or depending on the position of the switch it may to you seem open circuit , where in fact the switch is still sensing as closed
so in the case move the switch further out to desense the switching range ,

The switchs have small leds when they are triggered. the ethercat-module is showing the state too.
I will try to use them as limit-switch first. homing is working perfectly with all of them.

if homing is working then that proves they are ok ,
so the second part of my solution is correct , that they are either still switched due to proximity , and require desencing
as the switch never breaks , which shows the error , this is quite a common when using proximity switches .

And how could i realize that? Im not sure if i understand your solution.

to desense a proxinity sensore move the sensor back , making the gap wider .
and in some cases making the area it senses smaller , without knowing the exact location etc , it's difficutl to know what can be done . so moving the sensor away from the target decreaces it's sensitivity and or reducing the sensed area , and the opposite applies moving forward or making the target area larger will increace sensitivity .

For people that stumble over the same problem:
The Option HOME_IGNORE_LIMITS for every axis in the ini-file did the trick. Now its ignoring the Limit-Function while homing..
Thanks for the help anyways.

Regards, Jan